UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-Q QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY Investment Company Act file number: 811-06590 Morgan Stanley Insured Municipal Income Trust (Exact name of registrant as specified in charter) 1221 Avenue of the Americas, New York, New York 10020 (Address of principal executive offices) (Zip code) Ronald E. Robison 1221 Avenue of the Americas, New York, New York 10020 (Name and address of agent for service) Registrant's telephone number, including area code: 212-762-4000 Date of fiscal year end: October 31, 2007 Date of reporting period: January 31, 2007 ITEM 1. SCHEDULE OF INVESTMENTS. The Trust's schedule of investments as of the close of the reporting period prepared pursuant to Rule 12-12 of Regulation S-X is as follows: MORGAN STANLEY INSURED MUNICIPAL INCOME TRUST PORTFOLIO OF INVESTMENTS - January 31, 2007 (unaudited) PRINCIPAL AMOUNT IN COUPON MATURITY THOUSANDS RATE DATE VALUE --------- ------ -------- ------------- Tax-Exempt Municipal Bonds (152.0%) General Obligation (8.6%) $ 3,000 Los Angeles, California, Ser 2004 A (MBIA) 5.00% 09/01/24 $ 3,167,340 District of Columbia, 5,000 Refg Ser 1993 B (Ambac) 5.50 06/01/09 5,189,500 6,000 Refg Ser 1993 B (FSA) 5.50 06/01/10 6,267,420 4,110 Pennsylvania, First Ser 2003 (MBIA)[+/+] 5.00 01/01/19 4,376,862 4,000 Houston, Texas, Public Impr & Refg Ser 2001 B (FSA) 5.50 03/01/17 4,243,960 3,000 King County, Washington, Refg 1998 Ser B (MBIA) 5.25 01/01/34 3,061,710 2,500 Spokane School District #81, Washington, Ser 2005 (MBIA) 0.00# 12/01/23 2,394,975 ------- ----------- 27,610 28,701,767 ------- ----------- Educational Facilities Revenue (7.2%) 2,500 University of Arizona, 2003 Ser B COPs (Ambac) 5.00 06/01/23 2,607,950 University of California, 2,000 Ser 2003 B (Ambac) 5.00 05/15/22 2,103,300 3,120 Ser 2007 J (FSA)[+/+] 4.50 05/15/31 3,112,684 2,880 Ser 2007 J (FSA)[+/+] 4.50 05/15/35 2,873,246 3,000 District of Columbia, American Association for the Advancement of Science Ser 1997 (Ambac) 5.125 01/01/27 3,073,680 1,300 New Hampshire Health & Education Facilities Authority, University of New Hampshire Ser 2001 (Ambac) 5.125 07/01/33 1,360,242 1,000 University of Medicine and Dentistry, New Jersey, Ser 2004 COPs (MBIA) 5.00 06/15/29 1,048,610 4,200 New York State Dormitory Authority, School District Ser 2002 E (MBIA) 5.50 10/01/17 4,543,350 3,000 University of North Carolina at Wilmington, Student Housing Ser 2005 COPs (FGIC) 5.00 06/01/36 3,129,570 ------- ----------- 23,000 23,852,632 ------- ----------- Electric Revenue (24.5%) 4,000 Arkansas River Power Authority, Colorado, Power Ser 2006 (XLCA) 5.25 10/01/40 4,286,280 4,000 Lafayette, Louisiana, Utilities Ser 2004 (MBIA) 5.25 11/01/25 4,310,760 2,500 Missouri Joint Municipal Electric Utility Commission Plum Point Ser 2006 (MBIA) 5.00 01/01/26 2,652,150 5,000 Nebraska Public Power District, 2003 Ser A (Ambac) 5.00 01/01/35 5,228,500 Long Island Power Authority, New York, 4,000 Ser 2006 A (XLCA) 5.00 12/01/26 4,227,360 3,000 Refg Ser 2003 C (FSA) 5.00 09/01/28 3,149,010 6,000 North Carolina Municipal Power Agency # 1, Catawba Ser 2003 A (MBIA) 5.25 01/01/19 6,402,840 South Carolina Public Service Authority, Santee Cooper 10,000 2003 Ser A (Ambac) 5.00 01/01/27 10,457,000 4,000 2006 Ser A (MBIA) 5.00 01/01/36 4,222,120 Lower Colorado River Authority, Texas, 10,000 Refg Ser 1999 A (FSA) 5.875 05/15/16 10,539,600 5,000 Refg Ser 2001 (FSA) 5.00 05/15/26 5,142,350 8,780 Refg Ser 2002 (MBIA) 5.00 05/15/31 9,112,499 5,000 Intermountain Power Agency, Utah, 2003 Ser A (FSA) 5.00 07/01/21 5,290,500 6,000 Cowlitz County Public Utility District # 1, Washington, Production Ser 2006 (MBIA) 5.00 09/01/31 6,319,620 ------- ----------- 77,280 81,340,589 ------- ----------- Hospital Revenue (5.1%) 2,000 Illinois Finance Authority, Swedish American Hospital Ser 2004 (Ambac) 5.00 11/15/31 2,076,280 2,000 Indiana Health Facilities Financing Authority, Community Health Ser 2005 A (Ambac) 5.00 05/01/35 2,085,660 105 Missouri Health & Educational Facilities, SSM Health Care Ser 1998 A (MBIA) 5.00 06/01/22 107,162 1,500 Medical University Hospital Authority, South Carolina, FHA Insured Mtge Ser 2004 A (MBIA) 5.25 02/15/25 1,598,355 Amarillo Health Facilities Corporation, Texas, 3,020 Baptist St Anthony's Hospital Ser 1998 (FSA) 5.50 01/01/16 3,310,554 5,075 Baptist St Anthony's Hospital Ser 1998 (FSA) 5.50 01/01/17 5,598,943 2,000 Washington State Health Care Facilities Authority, Kadlec Medical Center Ser 2006 A (AGC) 5.00 12/01/30 2,087,520 ------- ----------- 15,700 16,864,474 ------- ----------- Industrial Development/Pollution Control Revenue (2.2%) 5,000 Hawaii Department of Budget and Finance, Hawaiian Electric Co Ser 1999 C (AMT) (Ambac) 6.20 11/01/29 5,328,650 2,000 Delaware County Industrial Development Authority, Pennsylvania, Aqua Inc Ser A 2005 (AMT) (FGIC) 5.00 11/01/37 2,086,240 ------- ----------- 7,000 7,414,890 ------- ----------- Public Facilities Revenue (11.4%) 15,000 Miami-Dade County School Board, Florida, 2003 Ser A (FGIC) 5.00 08/01/29 15,577,050 3,000 Orange County School Board, Florida, Ser 2001 A COPs (Ambac) 5.25 08/01/14 3,217,320 16,000 Hudson Yards Infrastructure Corporation, New York, 2007 Ser A (MBIA)[+/+] 4.50 02/15/47 15,821,040 3,000 Oregon Department of Administrative Services, Ser 2005 B COPs (FGIC) 5.00 11/01/24 3,172,920 ------- ----------- 37,000 37,788,330 ------- ----------- Recreational Facilities Revenue (6.9%) 3,000 Denver Convention Center Hotel Authority, Colorado, Refg Ser 2006 (XLCA) 5.00 12/01/30 3,157,080 2,000 District of Columbia Ballpark, Ser 2006 B-1 (FGIC) 5.00 02/01/31 2,104,340 Metropolitan Pier & Exposition Authority, Illinois, 3,000 McCormick Place Refg Ser 2002 B (MBIA) 0.00## 06/15/18 2,491,110 5,000 McCormick Place Ser 2002 A (MBIA) 5.25 06/15/42 5,307,000 2,400 Marion County Convention & Recreational Facilities Authority, Indiana, Refg Ser 2003 A (Ambac) 5.00 06/01/19 2,513,952 1,500 Baltimore, Maryland, Convention Center Hotel Ser 2006 A (XLCA) 5.25 09/01/39 1,622,535 1,000 Omaha Convention Hotel Corp, Nebraska, Ser 2002 A (Ambac) 5.50 04/01/18 1,073,430 New York City Industrial Development Agency, New York, 2,000 Queens Baseball Stadium - Ser 2006 (Ambac) 5.00 01/01/31 2,126,120 2,500 Yankee Stadium Ser 2006 (FGIC) 5.00 03/01/46 2,624,150 ------- ----------- 22,400 23,019,717 ------- ----------- Transportation Facilities Revenue (34.5%) 1,000 Phoenix Civic Improvement Corporation, Arizona, Sr Lien Airport Ser 2002 B (AMT) (FGIC) 5.75 07/01/19 1,080,640 9,000 Long Beach, California, Harbor Refg Ser 1998 A (AMT) (FGIC) 6.00 05/15/18 10,430,640 5,000 Atlanta, Georgia, Airport Ser 2004 C (FSA) 5.00 01/01/33 5,208,800 4,000 Illinois Toll Highway Authority, Priority Refg 1998 Ser A (FSA) 5.50 01/01/15 4,427,880 5,000 Chicago, Illinois, O'Hare Int'l Airport, Third Lien Ser 2005 A (MBIA) 5.25 01/01/25 5,388,850 8,000 Massachusetts Turnpike Authority, Metropolitan Highway 1997 Ser A (MBIA)[+/+] 5.00 01/01/37 8,122,320 5,000 Minneapolis - St Paul Metropolitan Airports Commission, Minnesota, Ser 2001 C (FGIC) 5.25 01/01/32 5,266,000 3,000 St Louis, Missouri, Lambert Int'l Airport Ser 2001 A (MBIA) 5.00 07/01/20 3,148,110 7,000 Nevada Department of Business & Industry, Las Vegas Monorail 1st Tier Ser 2000 (Ambac) 5.375 01/01/40 7,227,220 2,000 Delaware River Port Authority, New Jersey & Pennsylvania, Ser 1995 (FGIC) ** 5.50 01/01/26 2,022,820 4,000 New Jersey Transportation Trust Fund Authority, Ser 2005 C (FGIC) 5.25 06/15/20 4,339,240 Metropolitan Transportation Authority, New York, 3,000 Dedicated Tax Fund Refg Ser 2002 A (FSA) 5.25 11/15/24 3,203,070 10,000 Transportation Refg Ser 2002 A (FGIC) 5.00 11/15/25 10,490,500 10,000 Triborough Bridge & Tunnel Authority, New York, Refg 2002 E (MBIA) 5.25 11/15/22 10,676,900 9,000 Dallas-Fort Worth International Airport, Texas, Ser 2003 A (AMT) (FSA) 5.375 11/01/22 9,555,030 3,000 Harris County, Texas, Toll Road Ser Lien 2005 A (FSA) 5.25 08/15/35 3,115,530 4,000 Texas Turnpike Authority, Central Texas First Tier Ser 2002 A (Ambac) 5.50 08/15/39 4,283,080 3,000 Richmond Metropolitan Authority, Virginia, Refg Ser 2002 (FGIC) 5.25 07/15/22 3,390,180 Port of Seattle, Washington, 8,025 Passenger Facility Ser 1998 A (MBIA)[+/+] 5.00 12/01/23 8,206,920 5,000 Ser 2001 B (AMT) (MBIA) 5.625 02/01/24 5,243,800 ------- ----------- 108,025 114,827,530 ------- ----------- Water & Sewer Revenue (26.4%) 5,000 Los Angeles Department of Water & Power, California, Water 2004 Ser C (MBIA) 5.00 07/01/24 5,273,650 4,000 Oxnard Financing Authority, California, Water Ser 2004 (XLCA) 5.00 06/01/28 4,180,680 3,000 Sacramento Sanitation Districts Financing Authority, California, Ser 2006 (FGIC) 5.00 12/01/36 3,187,140 San Diego County Water Authority, California, 5,000 Ser 2002 A COPs (MBIA) 5.00 05/01/27 5,223,150 5,000 Ser 2004 A COPs (FSA) 5.00 05/01/29 5,260,100 5,000 Tampa Bay Water Authority, Florida, Ser 2001 A (FGIC) 5.00 10/01/28 5,164,400 5,000 Atlanta, Georgia, Water & Wastewater, Ser 2004 (FSA) 5.00 11/01/23 5,273,800 2,000 Augusta, Georgia, Water & Sewer Ser 2004 A (FSA) 5.25 10/01/39 2,145,120 Detroit, Michigan, 825 Sewage Refg Ser 2003 A (FSA) 5.00 07/01/26 860,343 2,390 Sewage Refg Ser 2003 A (FSA) 5.00 07/01/28 2,492,388 3,000 Sewage Disposal Ser 2001 A (FGIC) 5.125 07/01/31 3,163,260 5,080 Las Vegas Water District, Nevada, Impr & Refg Ser 2003 A (FGIC) 5.25 06/01/19 5,419,446 1,005 Cleveland, Ohio, Waterworks Impr & Refg 1998 Ser I (FSA) 5.00 01/01/23 1,023,341 5,000 Philadelphia, Pennsylvania, Water & Wastewater Ser 1998 (Ambac) 5.25 12/15/14 5,431,650 15,000 Houston, Texas, Combined Utility Refg 2004 Ser A (FGIC) 5.25 05/15/23 16,115,549 3,000 San Antonio, Texas, Water & Refg Ser 2002 A (FSA) 5.00 05/15/32 3,114,030 Seattle, Washington, 2,890 Water Refg 2003 (MBIA) 5.00 09/01/20 3,056,580 2,870 Water Refg 2003 (MBIA) 5.00 09/01/23 3,017,604 5,000 King County, Washington, Sewer Refg 2001 (FGIC) 5.00 01/01/31 5,178,100 2,900 West Virginia Water Development Authority, Loan Program II Refg 2003 Ser B (Ambac) 5.25 11/01/23 3,120,342 ------- ----------- 82,960 87,700,673 ------- ----------- Other Revenue (4.3%) 3,000 California, Economic Recovery Ser 2004 A (MBIA) 5.00 07/01/15 3,236,730 6,000 Golden State Tobacco Securitization Corporation, California, Enhanced Asset Backed Ser 2005 A (FGIC) 5.00 06/01/38 6,276,240 New York City Transitional Finance Authority, New York, 2,000 2000 Ser C (Ambac) 5.25 08/01/21 2,139,140 2,500 2000 Ser C (Ambac) 5.25 08/01/22 2,659,275 ------- ------------- 13,500 14,311,385 ------- ------------- Refunded (20.9%) 5,000 California Infrastructure & Economic Development Bank, Bay Area Toll Bridges Seismic Retrofit 1st Lien Ser 2003 A (FGIC) (ETM) 5.00 01/01/28 5,593,950 10,000 Bay Area Toll Bridges Seismic Retrofit 1st Lien Ser 2003 A (Ambac) (ETM) 5.00 01/01/28 11,187,900 15,000 Chicago, Illinois, Neighborhoods Alive 21 Ser 2001 A (FGIC) 5.50 01/01/11+ 15,910,950 3,275 Massachusetts Municipal Wholesale Electric Company, 1993 Ser A (Ambac) (ETM) 5.00 07/01/10 3,353,502 Detroit, Michigan, 2,175 Sewage Refg Ser 2003 A (FSA) 5.00 07/01/13+ 2,324,227 5,610 Sewage Refg Ser 2003 A (FSA) 5.00 07/01/13+ 5,994,902 5,000 New Jersey Educational Facilities Authority, Higher Education Ser 2002 A (Ambac)++ 5.25 09/01/12+ 5,373,200 5,000 Allegheny County Hospital Development Authority, Pennsylvania, Pittsburgh Mercy Health Ser 1996 (Ambac)(ETM) 5.625 08/15/18 5,379,300 10,000 Rhode Island Depositors Economic Protection Corporation, Refg 1992 Ser B (MBIA) (ETM) 6.00 08/01/17 10,933,600 3,000 Alexandria Industrial Development Authority, Virginia, Institute for Defense Analysis Ser 2000 A (Ambac) 5.90 10/01/10+ 3,246,660 ------- ------------- 63,060 69,298,191 ------- ------------- 478,535 Total Tax-Exempt Municipal Bonds (Cost $482,957,099) 505,120,178 ------- ------------- Short-Term Tax-Exempt Municipal Obligations (2.3%) 3,500 Missiouri Health & Education, Washington University Ser 1996 D (Demand 02/01/07) 3.68* 09/01/30 3,500,000 4,200 Harris County Health Facilities Authority, Texas, St Luke's Episcopal Hospital Ser 2001B (Demand 02/01/07) 3.73* 02/15/31 4,200,000 -------- ------------- 7,700 Total Short-Term Tax-Exempt Municipal Obligations (Cost $7,700,000) 7,700,000 ------- ------------- 486,235 Total Investments (Cost $490,657,099) 512,820,178 ------- ------------- (30,580) Floating Rate Note Obligations Related to Securities Held (-9.2%) ------- Notes with interest rates ranging from 3.44% to 3.65% at January 31, 2007 and contractual maturities of collateral ranging from 01/01/19 to 02/15/47 (c)@(Cost ($30,580,000)) (30,580,000) ------------- $455,655 Total Net Investments (Cost $460,077,099) (a) (b) 145.1% 482,240,178 ======== ------------- Other Assets in Excess of Liabilities 1.5 5,106,724 Preferred Shares of Beneficial Interest (46.6) (155,000,000) ----- ------------- Net Assets Applicable to Common Shareholders 100.0% $ 332,346,902 ===== ============= ---------- Note: The categories of investments are shown as a percentage of net assets applicable to common shareholders. AMT Alternative Minimum Tax. COPs Certificates of Participation. ETM Escrowed to Maturity. + Prerefunded to call date shown. ++ A portion of this security has been physically segregated in connection with open futures contracts in the amount of $178,750. [+/+] Underlying security related to inverse floater entered into by the Trust. @ Floating rate note obligation related to securities held. The interest rate shown reflects the rate in effect at January 31, 2007. # Currently a zero coupon security; will convert to 5.125% on December 1, 2008. ## Currently a zero coupon security; will convert to 5.30% on June 15, 2012. * Current coupon of variable rate demand obligation. ** Joint exemption in locations shown. (a) Securities have been designated as collateral in an amount equal to $30,007,467 in connection with open futures contracts and open interest rate swaps contracts. (b) The aggregate cost for federal income tax purposes approximates the aggregate cost for book purposes. The aggregate gross unrealized appreciation is $22,513,512 and the aggregate gross unrealized depreciation is $350,433, resulting in net unrealized appreciation of $22,163,079. (c) Floating Rate Note Obligations Related to Securities Held - The Trust enters into transactions in which it transfers to Dealer Trusts ("Dealer Trusts"), fixed rate bonds in exchange for cash and residual interests in the Dealer Trusts' assets and cash flows, which are in the form of inverse floating rate investments. The Dealer Trusts fund the purchases of the fixed rate bonds by issuing floating rate notes to third parties and allowing the Trust to retain residual interest in the bonds. The Trust enters into shortfall agreements with the Dealer Trusts which commit the Trust to pay the Dealer Trusts, in certain circumstances, the difference between the liquidation value of the fixed rate bonds held by the Dealer Trusts and the liquidation value of the floating rate notes held by third parties, as well as any shortfalls in interest cash flows. The residual interests held by the Trust (inverse floating rate investments) include the right of the Trust (1) to cause the holders of the floating rate notes to tender their notes at par at the next interest rate reset date, and (2) to transfer the municipal bond from the Dealer Trusts to the Trust, thereby collapsing the Dealer Trusts. The Trust accounts for the transfer of bonds to the Dealer Trusts as secured borrowings, with the securities transferred remaining in the Trust's investment assets, and the related floating rate notes reflected as Trust liabilities. The notes issued by the Dealer Trust have interest rates that reset weekly and the floating rate note holders have the option to tender their notes to the Dealer Trust for redemption at par at each reset date. At January 31, 2007, Trust investments with a value of $42,513,072 are held by the Dealer Trust and serve as collateral for the $30,580,000 in floating rate note obligations outstanding at that date. Contractual maturities of the floating rate note obligations and interest rates in effect at January 31, 2007 are presented in the "Portfolio of Investments". Bond Insurance: -------------- AGC Assured Guaranty Corporation. Ambac Ambac Assurance Corporation. FGIC Financial Guaranty Insurance Company. FSA Financial Security Assurance Inc. MBIA Municipal Bond Investors Assurance Corporation. XLCA XL Capital Assurance Inc. FUTURES CONTRACTS OPEN AT JANUARY 31, 2007: NUMBER OF DESCRIPTION, DELIVERY UNDERLYING FACE UNREALIZED CONTRACTS LONG/SHORT MONTH AND YEAR AMOUNT AT VALUE APPRECIATION -------------------- ---------- --------------------------- ----------------- ------------ 275 Short U.S. Treasury Notes 10 Year $(29,356,250) $572,409 ======== March 2007 INTEREST RATE SWAP CONTRACT OPEN AT JANUARY 31, 2007: NOTIONAL AMOUNT PAYMENTS PAYMENTS TERMINATION UNREALIZED COUNTERPARTY (000) MADE BY TRUST RECEIVED BY TRUST DATE APPRECIATION -------------------- -------- ---------------- ------------------------- ----------- ------------ J P Morgan Chase Co. $15,000 Fixed Rate 3.568% Floating Rate BMA 03/08/17 $256,802 ======== (Bond Market Association) GEOGRAPHIC SUMMARY OF INVESTMENTS BASED ON MARKET VALUE AS A PERCENT OF TOTAL INVESTMENTS Arizona ............................................................... 0.8% California ............................................................ 13.8 Colorado .............................................................. 1.5 District of Columbia .................................................. 3.4 Florida ............................................................... 5.0 Georgia ............................................................... 2.6 Hawaii ................................................................ 1.1 Illinois .............................................................. 7.4 Indiana ............................................................... 1.0 Louisiana ............................................................. 0.9 Maryland .............................................................. 0.3 Massachusetts ......................................................... 1.1 Michigan .............................................................. 3.1 Minnesota ............................................................. 1.1 Missouri .............................................................. 1.9 Nebraska .............................................................. 1.3 Nevada ................................................................ 2.6 New Hampshire ......................................................... 0.3 New Jersey ............................................................ 2.7 New York .............................................................. 10.3 North Carolina ........................................................ 2.0 Ohio .................................................................. 0.2 Oregon ................................................................ 0.7 Pennsylvania .......................................................... 3.6 Rhode Island .......................................................... 2.3 South Carolina ........................................................ 3.4 Texas ................................................................. 16.2 Utah .................................................................. 1.1 Virginia .............................................................. 1.4 Washington ............................................................ 6.7 West Virginia ......................................................... 0.6 Joint exemptions* .................................................... (0.4) ----- Total+ ................................................................ 100.0% ===== ---------- * Joint exemptions have been included in each geographic location. + Does not include open short future contracts with an underlying face value amount of $29,356,250 with unrealized appreciation of $572,409 and an open interest rate swap contract with an unrealized appreciation of $256,802. ITEM 2. CONTROLS AND PROCEDURES. (a) The Trust's principal executive officer and principal financial officer have concluded that the Trust's disclosure controls and procedures are sufficient to provide reasonable assurance that information required to be disclosed by the Trust in this Form N-Q was recorded, processed, summarized and reported within the time periods specified in the Securities and Exchange Commission's ("SEC") rules and forms, based upon such officers' evaluation of these controls and procedures as of a date within 90 days of the filing date of the report. The Trust's principal executive officer and principal financial officer have also concluded that the Trust's disclosure controls and procedures designed to ensure that information required to be disclosed by the Trust in this Form N-Q is accumulated and communicated to the Trust's management, including its principal executive officer and principal financial officer, as appropriate to allow timely decisions regarding required disclosure were effective. Management of the Trust has determined that as of and prior to November 30, 2006, the Trust's fiscal quarter end period, the Trust had a deficiency in its internal control over financial reporting related to the review, analysis and determination of whether certain transfers of municipal securities qualified for sale accounting under the provisions of Statement of Financial Accounting Standards No. 140 "Accounting for Transfers and Servicing of Financial Assets and Extinguishments of Liabilities." Since November 30, 2006, and prior to the issuance of the Trust's quarterly schedule of portfolio holdings, management has revised its disclosure controls and procedures and its internal control over financial reporting in order to improve the controls' effectiveness to ensure that transactions in transfer of municipal securities are accounted for properly. Management notes that other investment companies investing in similar investments over similar time periods had been accounting for such investments in a similar manner as the Trust. Accordingly, other investment companies are also concluding that there was a material weakness in their internal control over financial reporting of such investments. There was no impact to the net asset value of the Trust's shares or the Trust's total return for any period as a result of the changes in financial reporting of such investments. (b) There were no changes in the Trust's internal control over financial reporting that occurred during the fiscal quarter that has materially affected, or is reasonably likely to materially affect, the Trust's internal control over financial reporting. However, as discussed above, subsequent to November 30, 2006, the Trust's internal control over financial reporting was revised. ITEM 3. EXHIBITS. (a) A separate certification for each principal executive officer and principal financial officer of the registrant are attached hereto. 2 SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. Morgan Stanley Insured Municipal Income Trust /s/ Ronald E. Robison ------------------------------------- Ronald E. Robison Principal Executive Officer March 22, 2007 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed by the following persons on behalf of the registrant and in the capacities and on the dates indicated. /s/ Ronald E. Robison ------------------------------------- Ronald E. Robison Principal Executive Officer March 22, 2007 /s/ Francis Smith ------------------------------------- Francis Smith Principal Financial Officer March 22, 2007 3 EXHIBIT 3 A1 CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER I, Ronald E. Robison, certify that: 1. I have reviewed this report on Form N-Q of Morgan Stanley Insured Municipal Income Trust; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; 3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed; 4. The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) for the registrant and have: (a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared; (b) Omitted; (c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and (d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the second fiscal quarter of the period covered by this report that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and 5. The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions): (a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize, and report financial information; and (b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting. Date: March 22, 2007 /s/ Ronald E. Robison ---------------------------------------- Ronald E. Robison Principal Executive Officer 4 EXHIBIT 3 A2 CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER I, Francis Smith, certify that: 1. I have reviewed this report on Form N-Q of Morgan Stanley Insured Municipal Income Trust; 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report; 3. Based on my knowledge, the schedules of investments included in this report fairly present in all material respects the investments of the registrant as of the end of the fiscal quarter for which the report is filed; 4. The registrant's other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Rule 30a-3(c) under the Investment Company Act of 1940) for the registrant and have: (a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared; (b) Omitted; (c) Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of a date within 90 days prior to the filing date of this report, based on such evaluation; and (d) Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and 5. The registrant's other certifying officer(s) and I have disclosed to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions): (a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize, and report financial information; and (b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting. Date: March 22, 2007 /s/ Francis Smith ---------------------------------------- Francis Smith Principal Financial Officer 5