Mobile-based BancTrust, the holding company that operates BankTrust Bank, announced Tuesday that it has been purchased by Trustmark Corp. in a stock deal valued at approximately $55.4 million.

The move is designed to help Mississippi-based Trustmark expand into both the Florida and Alabama markets.

“BancTrust is a respected financial institution with long-standing customer relationships,” Trustmark President and CEO Daniel A. Grafton said in a news release. “This transaction provides an excellent opportunity for Trustmark to enhance its franchise by expanding into attractive Alabama markets, including Mobile and Montgomery, as well as increase scale in our existing Florida Panhandle markets.”

The deal values BancTrust stock at $3.08 per share based on Trustmark’s closing stock of $24.66 Friday. This is a 62 percent premium to BancTrust’s closing price of $1.90 on Friday.

According to media releases Tuesday morning, each BancTrust stockholder will receive 0.125 shares of Trustmark common stock for each BancTrust share they own.

BancTrust has 49 offices in Alabama and Florida, with $1.3 billion in loans and $1.8 billion in deposits as of March 31. Trustmark, based in Jackson, Miss., has more than 170 offices in Florida, Mississippi, Tennessee and Texas.

“We are delighted to become a part of the Trustmark organization and believe that the combination created by our two companies will enable us to better serve our customers through a broader array of products and services,” BancTrust President and CEO Bibb Lamar Jr. said in a company release. “Trustmark’s reputation, financial strength and capabilities will enhance our ability to meet the expanding needs of our customers. Our shareholders will be receiving shares of a very strong, successful banking company.”

Trustmark also said it plans to buy back $50 million in preferred stock and warrants from the Treasury Department. The stock and warrants were issued by BancTrust as part of the government’s bank bailout during the 2008 financial crisis.

According to media and business news outlets, both companies’ boards have unanimously approved the transaction, which is targeted to close in the fourth quarter. The acquisition still needs the approval of BancTrust shareholders.