British American Tobacco (BAT) on Friday offered to buy its U.S. partner Reynolds American for $47 billion. The cash-and-stock deal, if it goes through, would create the world’s biggest listed tobacco company.

The British group already owns a 42.2 percent stake in the American company. The offer to buy the remaining 57.8 percent stake values the rest of the company at $56.50 per share — a roughly 20 percent premium over its closing price Thursday. Of the $47 billion BAT has offered, $20 billion would be in cash and $27 billion in BAT shares.

Reynolds’ top-selling brands are Newport, Camel and Pall Mall, while BAT’s flagship brands are Dunhill and Lucky Strike.

“We have been a shareholder in Reynolds since its creation in 2004 and have benefited from its growth in the US market. The acquisition of Lorillard in 2015 has further strengthened Reynolds’s business,” BAT CEO Nicandro Durante said in a statement. “The proposed merger of our two great companies is the logical progression in our relationship and offers all shareholders a stake in a stronger, truly global tobacco and Next Generation Products company.”

The deal comes more than a year after Reynolds completed its own $25 billion acquisition of Lorillard.

BAT has not yet held talks with Reynolds. The company said the merger is subject to endorsement of Reynolds’s independent directors, and approvals from BAT and Reynolds shareholders.

In early trade Friday, BAT’s London-listed shares were up 2 percent. Reynolds’ shares on the NYSE, meanwhile, were up 1.9 percent in premarket trade.