The deal would have kick-started DraftKings' international expansion by giving it access to prominent British high street fixtures Ladbrokes and Coral, as well as the bwin and partypoker online brands.

"As far as why we walked away... It was really more about our confidence in our current trajectory in the U.S., our desire to focus on the U.S. and, ultimately, the value that we felt like we would be shedding by pursuing that asset," Robins said on a post earnings call with analysts.

Neither company has previously explained why deal talks fell through in late October.

Still, Robins did not rule out overseas acquisitions in the future.

There has been frenetic dealmaking in the industry as the United States opens up to sports betting and companies look to tap expertise forged in more developed gambling markets such as Britain.

"No one, not DraftKings, not MGM, not Caesars, not Flutter, not PointsBet - no one is going to be able to be a credible competitor for national leadership in the U.S. online betting market via organic growth alone," said Chris Grove, partner at research and consulting firm Eilers and Krejcik Gaming.

(Reporting by Eva Mathews and Praveen Paramasivam in Bengaluru; Editing by Devika Syamnath)