UPDATE 1-Online betting group Flutter sees US profit in 2023, shares spike

* Flutter predicts profit in the U.S. for first time

* Three-fold increase in U.S. customers in past 12 months

* 2021 EBITDA seen at 1.27-1.37 bln pounds vs 1.4 bln

* Permanent step change in scale seen in Australian unit (Adds details, CEO quotes)

By Padraic Halpin

DUBLIN, Aug 10 (Reuters) - Paddy Power, Betfair and Poker Stars owner Flutter Entertainment expects to turn a profit in the United States in 2023 after further heavy investment in the fast-growing market contributed to a 12% fall in first half earnings across the group.

It was the first time the world's largest online betting group predicted when its U.S. business would generate profits since a ban was lifted on sports betting there in 2018 and gambling took off.

Shares in Flutter were 6.9% higher at 163.1 euros by 0745 GMT.

Flutter said it had cemented its leadership position in the U.S. online market thanks to a three-fold increase in customers over the last 12 months. It expects to almost double the number of states it operates in to 19 over the next 18 months, including New York.

"We think the next 18 months are going to remain very big for customer acquisitions," Flutter Chief Executive Peter Jackson told analysts.

Revenue at its U.S. FanDuel unit surged 159% to 652 million pounds ($902.89 million), making it the second largest division across the group where revenue grew by 30%. It was the smallest division by sales a year ago.

Group earnings before interest, tax, depreciation and amortisation (EBITDA) fell to 597 million pounds on a pro-forma basis. Excluding an operating loss in the United States, earnings were 2% lower year-on-year.

Jackson said a 52% year-on-year increase in its Australian player base also suggested that its market leading Sportsbet unit may have experienced a permanent step change in scale.

The Dublin-based group said it expected full-year adjusted EBITDA of between 1.27 billion pounds and 1.37 billion pounds, including a U.S. loss of between 225 million and 275 million pounds, down from 1.4 billion pounds in 2020.

Jackson added that Flutter expected to appoint a new chief executive at FanDuel "fairly soon" - a prerequisite, he said, for a potential partial listing of the business which remains under consideration. ($1 = 0.7221 pounds) (Reporting by Padraic HalpinEditing by Louise Heavens and Tomasz Janowski)