SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 6-K REPORT OF FOREIGN PRIVATE ISSUER Pursuant to Rule 13a-16 or 15d-16 Under the Securities Exchange Act of 1934 For the month of October, 2005 ------------- Commission File Number 001-13908 --------- AMVESCAP PLC ------------------------------------------------ (Translation of registrant's name into English) 30 Finsbury Square, London EC2A 1AG, ENGLAND -------------------------------------------------------- (Address of principal executive offices) Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F. Form 20-F X Form 40-F ----- ----- Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ------ Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ------ Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934. Yes No X ------- ------- If "Yes" is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b): 82- N/A ------------- Description of document filed: BLOCKLISTING SIX MONTHLY RETURN ------------------------------- BLOCKLISTING SIX MONTHLY RETURN INFORMATION PROVIDED ON THIS FORM MUST BE TYPED OR PRINTED ELECTRONICALLY. To: The FSA Date: 11 October 2005 1. Name of applicant: AMVESCAP PLC 2. Name of scheme AMVESCAP PLC TRIMARK ACQUISITION 3. Period of return: From 11 APRIL To 10 OCTOBER 2005 4. Balance under scheme from previous return: 23,990,009 5. The amount by which the block scheme has been increased, if the scheme has been increased since the date of the last return 0 6. Number of securities issued/allotted under scheme during period: 400,000 7 Balance under scheme not yet issued/allotted at end of period 23,590,009 8. Number and class of securities originally listed and the date of admission 65,988,401 ORDINARY SHARES OF 25P EACH LISTED ON 11 OCTOBER 2000 9. Total number of securities in issue at the end of the period 812,080,657 ORDINARY SHARES OF 25P Name of contact ANGELA TULLY Address of contact 30 FINSBURY SQUARE, LONDON EC2 Telephone number of contact 020 7065 3652 Signed by ...............A. Tully.......................... Director/assistant company secretary/suitably experienced employee/duly authorised officer, for and on behalf of Name of applicant ......AMVESCAP PLC................................... If you knowingly or recklessly give false or misleading information you may be liable to prosecution. SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. AMVESCAP PLC ------------------------------ (Registrant) Date 11 October, 2005 By /s/ Angela Tully ---------------- -------------------------- (Signature) Angela Tully Assistant Company Secretary