NORWICH – NBT Bancorp Inc. and Hampshire First Bank (HFB) announced Wednesday that they have entered into a definitive agreement under which Hampshire First Bank will merge with and into NBT’s banking subsidiary, NBT Bank, N.A.

The merger is valued at approximately $45 million and is expected to close early in the second quarter of 2012 subject to customary closing conditions, including receipt of regulatory approvals and approval by the stockholders of HFB.

HFB is a state-chartered commercial community bank with five locations in southern New Hampshire and assets of $273 million as of Sept. 30. NBT is headquartered in upstate New York and operates a network of 128 banking locations in four states, including New York, Pennsylvania, Vermont and Massachusetts. The financial services holding company had assets of $5.5 billion as of Sept. 30.

“We are pleased to have this opportunity to join forces with Hampshire First Bank,” said NBT President and CEO Martin Dietrich. “We share a strong commitment to community and a focus on putting customers first that will contribute to the success of this partnership.” Dietrich also noted that this extension of NBT’s footprint into New Hampshire fits well with recent strategic growth initiatives, including NBT’s organic expansion into the Burlington, Vt., market beginning in 2009 and a recent four-branch acquisition in Berkshire County, Mass., completed in October.