Two of the biggest brands in online betting are getting together.

Flutter Entertainment, which owns Irish gambling firm Paddy Power, is buying The Stars Group of Canada, owner of the world’s largest poker site, PokerStars.

The companies said Wednesday that they had agreed an all-share merger to create the world’s biggest online betting and gaming company. At Tuesday’s closing prices the two companies were worth nearly $12 billion, according to Refinitiv data.

The combined group would have about four million active customers in more than 100 international markets, they said in a statement.

In addition to Paddy Power, Flutter owns fantasy sports brand FanDuel and Australia’s Sportsbet.

The companies say the global gambling market was worth about $450 billion in 2018, with online betting accounting for about 11%.

“Flutter and TSG are confident that there remains a long runway of growth left for online and mobile gambling,” they added.

The combined group’s annual revenue would have been £3.8 billion ($4.7 billion) in 2018. The United States will be a big focus for the new group. The US Supreme Court last year cleared the way for states to legalize sports betting.

The deal will result in Flutter shareholders owning about 55% of the combined entity, with TSG shareholders owning just over 45%.