There is one less dark liquidity pool operator as State Street plans to exit the business and sell its BlockCross ATS to agency broker Instinet for an undisclosed sum.

“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, in a prepared statement.

The parties expect the deal to close within 30 to 60 days of the announcement.

Instinet plans to maintain the team that operates BlockCross and will move them to the brokerage’s Boston office, according to officials.

State Street acquired the BlockCross platform when the custodian bank purchased the Boston-based Pulse Trading in the second half of 2011.

“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,” Nick Bonn, Global Head of Portfolio Solutions for State Street Global Markets. told Traders Magazine at the time.

The new acquisition should add additional access to dark liquidity provided by Instinet’s Continuous Block Crossing System (CBX), which the brokerage launched in 2009.

According to ATS volume data State Street Global Markets reported to FINRA on June 19, BlockCross witnessed 1,466 trades for an approximately 15.2 million shares while Instinet reported that CBX saw 339,902 trades for approximately 73.7 million shares over the same period.

The acquisition of BlockCross represents the second transaction in as many months to expand its offering to the buy side.

In May, the broker launched its Plazma research payment management platform.

The provider-neutral platform lets research procurement management systems to transfer quality assessment data to Plazma so that investment managers can review, edit, and confirm the information before authorizing payments for the research.