Instinet Holdings Incorporated today announced that it has entered into a definitive agreement to acquire State Street’s BlockCross ATS, an industry leading alternative trading system (ATS).

Terms were not disclosed.

The transaction is expected to close in approximately 30-60 days, subject to satisfaction of closing conditions.

“The addition of the BlockCross ATS to the Instinet product suite creates a unique liquidity offering helping our clients’ pursuit of best execution,” said Jonathan Kellner, CEO of Instinet Holdings Incorporated. “This acquisition is another milestone in Instinet’s history of delivering industry leading technology and execution services to the global market place.”

“This sale will allow us to focus on our core transition management and agency brokerage solutions and areas where we can add the most value for our clients, including continued support of brokerage clients that are also BlockCross subscribers,” said Nick Bonn, Global Head of Portfolio Solutions for State Street Global Markets.

The deal is intended to give BlockCross clients continued access to State Street’s unique liquidity while leveraging Instinet’s capabilities to deploy trading solutions world-wide. Instinet will operate the ATS using the same BlockCross team, who will join Instinet’s office in Boston.