Trustmark Corp. is buying BancTrust Financial Group Inc. in a stock deal valued at approximately $55.4 million, helping the bank to expand in Florida and Alabama.

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

Each BancTrust stockholder will receive 0.125 shares of Trustmark common stock for each BancTrust share they own.

BancTrust, which is based in Mobile, Ala., 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.