Instinet Group Inc. reports it has received a competing offer for its institutional brokerage business.

The company has agreed to a deal with the Nasdaq Stock Market Inc. that will see Nasdaq buy the firm, keep the trading platform, and spin off the institutional division to private equity firm, Silver Lake Partners.

However, the firm now says it has received a letter from Third Avenue Management proposing to buy the assets and liabilities of the institutional broker. It notes that the proposal described in the letter is subject to, among other things, the completion of due diligence by Third Avenue Management.

Instinet’s board of directors is reviewing the letter in a previously scheduled meeting. However, it notes that, under its merger agreement with Nasdaq, “We are subject to restrictions with respect to third party proposals of the type contained in the letter from Third Avenue Management.”