Downeast Pension Services Inc. of New Gloucester has been acquired by Norwich, New York-based NBT Bank for an undisclosed sum.

NBT expanded into Maine in 2014 to focus on commercial lending, and with the acquisition of Downeast Pension it is now adding retirement benefits management to its list of services in the state.

Downeast Pension is a retirement plan services company with 25 employees that provides third-party administration for company-sponsored retirement plans.

The company will continue to operate as a standalone business, retaining its employees and brand at its New Gloucester headquarters, according to a news release. Rene Morin will continue in his role as president of Downeast Pension, it said.

NBT has a network of over 150 banking locations in six states including New York, Pennsylvania, Vermont, Massachusetts, New Hampshire and Maine. It had assets of $8.9 billion as of Dec. 31 and is traded on the NASDAQ exchange under the symbol NBTB.