Paddy Power Betfair parent Flutter Entertainment reported a 10% rise in third-quarter revenue to £533m, helped by a 67% jump in the US where it raised its outlook.
Flutter last month agreed to buy Toronto-listed Poker Stars operator Stars Group in a $6 billion share deal set to create the world's largest online betting and gambling company by revenue.
It retained its full year group EBITDA guidance excluding the US at £420-440m. That is down from £475m last year, excluding investment in its US unit.
Part of its response has been a push into the US market where sports betting rules have been relaxed.
Flutter last year merged its US unit with fantasy sports company FanDuel.
It said third-quarter revenue in the US market rose by 67% as it pushed into five new states - two online in Pennsylvania and West Virginia and three in retail in Iowa, New York and Indiana.
It raised its outlook for the U.S. market to a loss in earnings before interest, tax, depreciation and amortisation of £40-45m versus a loss of £55m forecast earlier.
Flutter said it had more than 250,000 US online sportsbook customers, up from just over 200,000 at the time of the TSG merger announcement on October 2.
It also said its US casino revenues surged 174% on an annual basis.
Revenues were down 1% in its main online division dominated by the Paddy Power and Betfair brands due to the cost of implementing responsible gambling measures, tough year-on-year comparisons and the banning of online betting in some unregulated markets.
With Australia set to account for around 15% of combined income of the merged group, revenues at Flutter's market leading Sportsbet brand rose by 19%.
Flutter's chief executive Peter Jackson said that both the Paddy Power and Betfair brands continued to make good progress in building more recreational customer bases through enhanced responsible gambling measures.
"While revenues in the quarter were impacted by this ongoing work, we remain confident that the changes being made will improve the sustainability of future growth and lead to a more diversified customer base for both brands," he added.