Lake Michigan Credit Union has signed a definitive agreement to buy Encore Bank, a Naples-based financial institution with a branch in Sun City Center.

The deal will give Lake Michigan Credit Union, with existing branches in Naples, Immokalee, and Bonita Springs, six more branches in Florida and an additional $400 million in assets.

Lake Michigan Credit Union is the largest credit union in Michigan with $5.2 billion in assets. Although it is headquartered in Grand Rapids, it has members who live in Florida for at least part of the year.

The credit union will strengthen and expand its presence in Southwest Florida with the Encore Bank acquisition, Sandy Jelinski, president and CEO, said in a press release.

It’s the latest in an increasing number of deals in which a credit union buys a bank. Seven banks agreed to sell to credit unions in the 18 months ended June 15. The growing trend has prompted Achieva Credit Union in Dunedin, which bought Calusa Bank in 2015, to form a specialized mergers and acquisitions consulting practice group to help credit unions and banks find suitable partners, guide them through transactions and help merge operations.