The Nasdaq Stock Market Inc. announced that it has entered into a definitive agreement to acquire Shareholder.com. Terms of the transaction were not disclosed.

Shareholder.com is a privately held, Massachusetts-based firm specializing in shareholder communications and investor relations intelligence services. After the acquisition it will operate as a wholly owned subsidiary of Nasdaq . It currently serves over 1,000 clients, including 396 companies currently listed on Nasdaq .

Nasdaq says that this transaction will enable it to offer Shareholder.com’s comprehensive suite of investor relations and intelligence services to its 3,200 listed companies and other publicly held companies.

“Nasdaq is continuing to find new ways to support public companies by offering investor relations and other services essential to operating a publicly held company,” Bruce Aust, executive vice president of Nasdaq commented, “This acquisition furthers our strategy to maximize the value companies receive from Nasdaq , and to attract new listings. It is also in keeping with Nasdaq’s philosophy to maximize transparency and to give investors equal access to information.”

“Shareholder.com and Nadaq have developed a very successful relationship in the 15 months we’ve been working together that’s strongly benefited our client companies,” commented Ronald Gruner, Shareholder.com’s founder and president. “This acquisition is the logical next step that assures we will continue providing the most innovative technology and client satisfaction to public companies.”

This acquisition follows Nasdaq’s purchase of Carpenter Moore, management liability insurance specialists, last September, and the creation of Independent Research Network, a joint venture with Reuters to provide public companies with research coverage.

Nasdaq’s acquisition encompasses Shareholder.com’s three offices, located in Maynard, Massachusetts, San Francisco, and Amsterdam.

The transaction is expected to close in the first quarter of 2006.