13F-HR 1 c42423_13fhr.txt UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 13F FORM 13F COVER PAGE Report for the Calendar Year or Quarter Ended: 03/31/06 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: GAM USA Inc. Address: 330 Madison Avenue New York, NY 10017 13F File Number: 28-7714 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: Kenneth A. Dursht Title: General Counsel Phone: 212-407-4766 Signature, Place, and Date of Signing: Kenneth A. Dursht New York, New York 04/20/06 Report Type (Check only one.): [ X] 13F HOLDINGS REPORT. [ ] 13F NOTICE. [ ] 13F COMBINATION REPORT. List of Other Managers Reporting for this Manager: I AM SIGNING THIS REPORT AS REQUIRED BY THE SECURITIES EXCHANGE ACT OF 1934. FORM 13F SUMMARY PAGE Report Summary: Number of other Included Managers: 2 Form 13F Information Table Entry Total: 223 Form 13F Information Table Value Total: $1,248,544 List of other Included Managers No. 13F File Number Name 01 00-00000-000 GAM International Management Limited 02 00-00000-000 GAM London Limited GB Form 13F Information Table GAM USA Inc. Page 1 of 9

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GAM USA INC 13F-HR