Australian online sports betting operator Sportsbet is suing rival Crownbet over the latter’s attempt to rebrand as Sportingbet.

On Monday, Australian legal publication Lawyerly reported that Sportsbet, a division of UK-listed gambling operator Paddy Power Betfair, has filed a lawsuit alleging that Crownbet was infringing on Sportsbet’s trademark by trying to trademark the Sportingbet name.

Crownbet, which was acquired by Canadian online gambling giant The Stars Group in February, announced earlier this month that it planned to rebrand its expanded operations under the currently dormant Sportingbet brand. Crownbet assumed ownership of the Sportingbet brand after acquiring the Aussie operations of UK bookmaker William Hill in March.

In May, Crownbet filed an application to trademark Sportingbet and this month applied to register the name Sportingbet Pty Ltd with the Australian Securities and Investments Commission. Sportsbet reportedly sent Crownbet a letter demanding the withdrawal of the application and requesting that Crownbet ditch its Sportingbet rebranding efforts. Crownbet’s solicitors rejected Sportsbet’s demands and the fight was officially on.