State Street has become a core shareholder in E-Crossnet, the buy-side crossing network for trading in European equities.
State Street's decision to join E-Crossnet should boost liquidity on the platform, which has matched £16 billion in European equities since launch in March 2000. The US banking group is understood to have bought a 20% stake in the business.
Original investors Barclays Global Investors and Legal & General have also raised their shareholdings, while co-founder Merrill Lynch Investment Management has seen its stake shrink.
States Street joins 12 other participants and minority shareholders who between them have $5 trillion in assets under management.
State Street's Lattice system was one of the first electronic networks in crossing US equities in the early 1990s.
"We're a firm believer in the power of crossing," says Timothy Harbert, chairman and CEO of State Street Global Advisors. "We were one of the first money managers to receive an exemption from the US Department of Labor in the 1980s to cross stocks internally within our index portfolios."