Pittsfield-based Berkshire Hills Bancorp expects to close its acquisition of Needham’s Greenpark Mortgage Corp. today, both institutions confirmed to Banker & Tradesman.

The transaction was originally expected to close by the end of the first quarter.

Under the agreement, Berkshire acquires Greenpark’s business model, certain assets and its entire staff, including Paul Gershkowitz and Patty O’Meara, who founded the residential correspondent lending firm in 2001.

Greenpark will be run as a division of Berkshire. Gershkowitz and O’Meara will be Berkshire first vice presidents.

Berkshire has been on an acquisition spree in the last year. Last week, it closed its acquisition of Hartford, Conn.-based Connecticut Bank & Trust Co. Last year, it acquired Legacy Bancorp, also of Pittsfield, as well as Rome Bancorp, of Rome, N.Y.

Through the acquisitions, Berkshire has grown to about $4 billion in assets and more than 60 branches.