State Street ( STT) agreed to acquire closely held foreign exchange trading platform Currenex for $564 million in cash.

Boston-based State Street said it expects the transaction to be neutral to 2007 results and slightly accretive to earnings in 2008.

"Today's announcement reflects our proven strategy of acquiring key technologies and platforms that enhance capabilities for our customers and expand our market share in high growth areas such as foreign exchange. This acquisition also diversifies State Street's trading customer base beyond traditional asset managers to include more active currency managers and hedge funds," said Joseph L. Hooley, vice chairman and global head of investment servicing and investment research and trading at State Street. "The future of global electronic foreign exchange trading will be determined by who can provide the most efficient technology solutions that allow quicker access to markets and flexible, comprehensive trading solutions."