Exhibit 24.1



POWER OF ATTORNEY



Each of the undersigned, as a member of the Board of Directors (the Board), or as an officer, or as a member of a committee of the Board, or
in two or more of such capacities, of Instinet Group Incorporated, a Delaware corporation (Instinet), hereby constitutes and appoints JOHN F. FAY and PAUL A. MEROLLA, and each of them singly, his or her true and lawful attorney-in-fact
and agent, with full power of substitution and resubstitution, to act, for him or her and in his or her name, place and stead and on his or her behalf, in any and all capacities, to sign Instinets Annual Report on Form 10-K for the fiscal year
ended December 31, 2004, and any and all amendments to such Form 10-K and other documents relating thereto, and to file on behalf of Instinet such Annual Report on Form 10-K and any such amendments, with all exhibits thereto, and any and all other
information and documents in connection therewith, with the Securities and Exchange Commission (the SEC), hereby granting unto said attorneys-in-fact and agents, and each one of them, full power and authority to do and perform any and
all acts and things requisite to enable Instinet to comply with the Securities Exchange Act of 1934 and any rules and regulations and requirements of the SEC in respect thereof in connection with the filing of Instinets Annual Report on Form
10-K as fully to all intents and purposes as he or she might or could do in person as a director of Instinet, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any one of them, may lawfully do or cause to be done by
virtue hereof.



|                                           |  |                                                 |  | 
|------------------------------------------ |  | ----------------------------------------------- |  | 
|SIGNATURE                                  |  | TITLE                                           |  | 
|                                           |  |                                                
|/s/ Edward J. NicollName: Edward J. Nicoll |  | Chief Executive Officer and Director            |  | 
|                                           |  |                                                
|/s/ John F. FayName: John F. Fay           |  | Chief Financial Officer                         |  | 
|                                           |  |                                                
|/s/ Ian StrachanName: Ian Strachan         |  | Director and Chairman of the Board of Directors |  | 
|                                           |  |                                                
|/s/ Thomas H. GlocerName: Thomas H. Glocer |  | Senior Director                                 |  | 
|                                           |  |                                                
|/s/ John C. BogleName: John C. Bogle       |  | Director                                        |  | 
|                                           |  |                                                
|/s/ David GrigsonName: David Grigson       |  | Director                                        |  | 
|                                           |  |                                                
|/s/ Peter J. JobName: Peter J. Job         |  | Director                                        |  | 





---

|                                           |  |          |  | 
|------------------------------------------ |  | -------- |  | 
|                                           |  |         
|/s/ John KasichName: John Kasich           |  | Director |  | 
|                                           |  |         
|/s/ Kay KoplovitzName: Kay Koplovitz       |  | Director |  | 
|                                           |  |         
|/s/ C. Kevin LandryName: C. Kevin Landry   |  | Director |  | 
|                                           |  |         
|/s/ Stephen PagliucaName: Stephen Pagliuca |  | Director |  | 
|                                           |  |         
|/s/ Devin WenigName: Devin Wenig           |  | Director |  | 
|                                           |  |         
|/s/ Robin JosephsName: Robin Josephs       |  | Director |  | 



Dated: March 7, 2005



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