JACKSON, Miss. — The long-awaited merger between BancTrust, the holding company of BankTrust, and Mississippi-based Trustmark was official at the close of business Friday. And, over the long, President’s Day weekend, the signage of many BankTrust banks will begin to change.

“The legal merger does occur as of the close of business [Friday],” Melanie A. Morgan, senior vice president and director of corporate communications and board relations for Trustmark, said in an email to the Times-Journal Thursday evening. “In short, customers will notice a change in the signage over the upcoming weekend. At a minimum, all locations will have temporary Trustmark signage installed over the President’s Day weekend, with permanent signage to be phased in over the next few weeks.”

Morgan said the conversion of the bank’s system will take place over the March 22 weekend.

The merger between the two banks, which will carry the Trustmark name, was announced last May and was valued at $55.4 million. Through a few pauses in the process, the deal received regulatory approval in mid-January, leading to Friday’s completion.

Trustmark, based in Jackson, Miss., has more than 170 offices in Florida, Mississippi, Tennessee and Texas.

“We are delighted to be joining forces with Trustmark and look forward to continuing to serve our customers as part of a strong, $12 billion regional banking organization,” BancTrust President and CEO W. Bibb Lamar Jr. said in a January statement, announcing the regulatory approval.

In information shared last year, during an analyst presentation after the merger was announced, Gerald R. Host, President and CEO of Trustmark, said the move is one that allows Trustmark to move into many Alabama markets, where BankTrust was the dominant bank, and into an overall market, where he sees growth on the horizon.

Information in the presentation showed BankTrust had a top three position in five of the 10 markets mentioned, and held the top position in four of those markets.

The report showed BankTrust was the market’s No. 1 bank, with 28.1 percent of the market share in Selma. The bank also held the top position in the Brewton, Monroeville and Greenville markets. In Walton County, Fla., BankTrust had the No. 2 spot. In Mobile, BankTrust was the No. 5 bank with an 8.5 percent market share.

“We look forward to welcoming customers and associates of BancTrust to the Trustmark family,” Host said in last month’s release. “Expansion into attractive Alabama markets, including Mobile and Montgomery, as well as increasing scale in existing Florida Panhandle markets, represents a great opportunity for Trustmark.