Municipal Employees Credit Union in Baltimore plans to implement core banking software from Fidelity National Information Services Inc.

Fidelity, of Jacksonville, Fla., said the credit union would use its Miser application, which allows financial institutions to perform real-time transaction processing. It can support both retail and commercial accounts and mortgages.

The credit union, which has 90,000 members and assets of more than $830 million, said it wanted a more advanced core banking system to support its expansion in the Baltimore area.

"The Miser system's real-time efficiencies and breadth of functionality will enable MECU to continue exceeding members' expectations as we grow," Bert J. Hash Jr., the credit union's president and chief executive, said Wednesday in a Fidelity press release.