North Middlesex Savings Bank

Rick Bennett, the CEO of Main Street Bank and its predecessor in Marlborough for 17 years, is retiring, the bank announced Tuesday.

The long-time Assabet Valley bank is riding the industry wave of expansion and growth.

The merger of Marlborough Savings Bank and North Middlesex Savings Bank was made official on April 1. The two longtime banks first said last July they planned to merge, and earlier this year they unveiled the new name and logo for Main Street Bank.

Marlborough Savings Bank and North Middlesex Savings Bank have a name for their new company post-merger.

Two area mutual banks have announced that they have agreed to a merger that would create a bank with nearly $1 billion in assets and $95 million in equity across 14 branches.