Investment Technology Group (ITG)

EXPLANATORY NOTE

This Amendment No. 1 on Form 10-K/A is being filed to re-file, as amended, the Report of Independent Registered Public Accounting Firm under Item 9A of our Annual Report on Form 10-K for the fiscal year ended December 31, 2004, as filed with the Securities and Exchange Commission on March 15, 2004 (the “Original Filing”).  The sole reason we are filing this Form 10-K/A is to include the following text at the end of the fourth paragraph of the Report of Independent Registered Public Accounting Firm, which was inadvertently omitted from the Original Filing:

“Also, in our opinion, Investment Technology Group, Inc. maintained, in all material respects, effective internal control over financial reporting as of December 31, 2004, based on criteria established in Internal Control — Integrated Framework issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).”

As a result of this amendment, (1) the certifications pursuant to Section 302 and Section 906 of the Sarbanes-Oxley Act of 2002, filed and furnished, respectively, as exhibits to the Original Filing, have been re-executed and re-filed as of the date of this Form 10-K/A and (2) a revised Consent of Independent Registered Public Accounting Firm, dated March 23, 2005, as a result of the revisions described above is being filed.

Except for the amendments described above, this Form 10-K/A does not modify or update other disclosures in, or exhibits to, the Original Filing.

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