PITTSFIELD, Mass. — The county's largest bank is getting bigger with the addition of 20 retail bank branches in New York.

Berkshire Bank, a subsidiary of Berkshire Hills Bancorp. Inc., has entered into a purchase-and-assumption agreement for bank branches from Bank of America. The branches are located in New York markets within or contiguous to markets currently served by Berkshire.

The acquired branches have approximately $640 million in total deposits and $5 million in loans. Both banks will be working to ensure a seamless transition for customer accounts; employees will transfer over to Berkshire Bank.

This acquisition is subject to regulatory approval from