INET Offers Subscribers Option to Display Volume Through Bloomberg.

NEW YORK -- Inet ATS, Inc. ("INET"), a subsidiary of Instinet Group Incorporated (NASDAQ: INGP), announced today its participation in Bloomberg's Market Maker Activity (MKAC) page. As a result of INET's participation, INET subscribers now have the option of providing their INET volume to Bloomberg to be aggregated with volume executed in other marketplaces.

"With this new service, INET is providing its subscribers with a valuable tool for more effectively marketing their services," said Alex Goor, President of INET. "Brokers providing liquidity to investors in certain securities will now be able to refer their customers and investors to a third-party site that accurately reflects their contributions."

Prior to INET's relationship with Bloomberg, market participants relied on incomplete sources that failed to include volume executed on INET, one of the largest markets for NASDAQ-listed securities that now accounts for approximately 27.3% of the daily NASDAQ- listed volume.* INET subscribers can take advantage of this new service immediately by contacting their INET Sales Representative at 212-231-5150.

About INET

INET, the Electronic Marketplace, provides its more than 800 U.S. broker-dealer subscribers access to one of the largest electronic marketplaces for U.S. over-the-counter securities, with approximately 27.3 percent of NASDAQ-listed equity trading.* Representing the consolidated order flow of the former Instinet ECN and former Island ECN, INET collects, prioritizes, displays and matches orders within its subscriber network and, through the use of advanced technology, offers routing services for its U.S.-registered broker-dealer subscribers. INET's trading platform is fast, anonymous, reliable and cost-efficient, designed for scalability in high-speed, high-volume electronic trading.

This news release is for information purposes only and is not intended as an offer or solicitation with respect to the purchase or sale of any security. While Instinet Group believes the information contained herein is reliable, we do not guarantee its accuracy, and it may be incomplete or condensed. These statements speak only as of this news release and Instinet undertakes no obligation to update publicly any of the information contained herein, in light of new information or future events.

(C) 2004 Inet ATS, Inc. All rights reserved. INET and the INET logo are service marks in the United States. Inet ATS, Inc., member NASD/NSX/SIPC, branded as INET, is a subsidiary of Instinet Group Incorporated.

* NASDAQ-listed market share reflects July 2004 transaction information. For a description of how we calculate INET's share volumes, see "Management's Discussion and Analysis of Financial Condition and Results of Operations - Calculation of Volume - INET, the Electronic Marketplace " in our Form 10-Q for the fiscal quarter ended June 30, 2004.

This news release may be deemed to include forward-looking statements relating to Instinet. Certain important factors that could cause actual results to differ materially from those disclosed in such forward-looking statements are included in the Instinet Annual Report Form 10-K dated for the period ended December 31, 2003 and other documents filed with the SEC and available on the Company's web site.