Burger King parent company Restaurant Brands International (RBI), announced plans to acquire Popeyes Louisiana Kitchen, the southern fried chicken chain for $1.8bn.

Ontario-based RBI was formed in 2014 when Burger King merged with the Canadian donut shop Tim Hortons.

It is majority-owned by 3G Capital, the Brazilian private equity firm, a big investor in Kraft Heinz, the US food giant which last week failed to merge with Unilever, the Anglo-Dutch consumer goods company.

RBI will pay $79 a share to buy Popeyes, which opened its first shop 45 years ago in New Orleans.

The deal will be financed with cash and a loan from JPMorgan and Wells Fargo.

“With this transaction, RBI is adding a brand that has a distinctive position within a compelling segment and strong U.S. and international prospects for growth,” said Daniel Schwartz, RBI’s chief executive.

Popeyes, with 2,631 shops worldwide, boasts celebrity fans including the popstar Beyonce.

Popeye’s shares surged by almost 20 percent in pre-market trading to $78.69 a piece.

“RBI has observed our success and seen the opportunity for exceptional future unit growth in the U.S. and around the world. The result is a transaction that delivers immediate and certain value to the Popeyes shareholders,” said Cheryl Bachelder, chief cxecutive of Popeyes in a statement.

The transaction is expected to close by early April 2017.