DUBLIN, Nov 10 (Reuters) - Paddy Power, Betfair and Poker Stars owner Flutter Entertainment upgraded its full-year earnings guidance on Wednesday after strong customer growth across all key regions boosted third-quarter revenues by 30%.

The world's largest online betting group expects full-year earnings before interest, tax, depreciation and amortization (EBITDA) of 1.275 billion to 1.350 billion pounds ($1.69 billion-$1.79 billion), up from the 1.175 to 1.325 billion pounds forecast in August.

That excluded its heavy investment into the United States, where an EBITDA loss of 160 million to 180 million pound is expected for 2020, also up on the 140 million to 160 million previously flagged.

Flutter raised 800 million pounds in May to drive growth as more U.S. states relax betting rules and said on Wednesday its FanDuel and FoxBet brands retained their market leading positions with a 46% share of online sports betting.

New U.S. customers grew at a better than expected rate and average daily group customers were up 41% year-on-year. Revenues grew by 76% year-on-year in Australia and by 14% in its mainly Britain and Ireland-based Paddy Power and Betfair online division.

After a jump in poker and gaming players in the first half more than compensated for a two-month global sports shutdown earlier in 2020, revenue trends at PokerStars returned to normal in the third quarter

The COVID-19 pandemic called a near total halt to all sports events for two months from mid-March, with some like the 2020 European Championships postponed by a year. Flutter said its improved outlook assumed no further material disruption.

($1 = 0.7530 pounds) (Reporting by Padraic Halpin; Editing by Edmund Blair)