UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 Form 13F Cover Page Report for the Calendar Year or Quarter Ended: December 31, 2005 Check here if Amendment [ ]; Amendment Number: _______ This Amendment (Check only one): [ ] is a restatement. [ ] adds new holdings entries. Institutional Investment Manager Filing this Report: Name: Federated Advisory Services Company Address: Federated Investors Tower 1001 Liberty Avenue Pittsburgh, PA 15222-3779 Form 13F File Number: 28-10899 The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it; that all information contained herein is true, correct and complete; and that it is understood that all required items, statements, schedules, lists, and tables are considered integral parts of this form. Person Signing this Report on Behalf of Reporting Manager: Name: David J. Brennen Title: Compliance Officer Phone: (412) 288-7052 Signature, Place, and Date of Signing: /s/David J. Brennen Pittsburgh, PA February 9, 2006 Report Type (Check only one): [ ] 13F HOLDING REPORT. [ X ] 13F NOTICE. [ ] 13F COMBINATION REPORT. List of Other Managers Reporting for this Manager: Form 13F File Number: 28-04375 Name: Federated Investors, Inc.