A US federal judge on Friday temporarily blocked ESPN, Fox and Warner Bros Discovery from launching a joint sports streaming service as the question of whether the platform violates antitrust laws works through the courts.
Fubo, a sports streamer that brought the lawsuit in April, called the injunction a "victory."
ESPN, Warner Bros and Fox announced in February that they would create the new streaming service, called Venu Sports.
District Judge Margaret Garnett on Friday granted Fubo's request to block the launch in part because "Fubo is likely to be successful in proving its claims that the (venture) will violate this country's antitrust laws."
She also added that "Fubo and American consumers will face irreparable harm in the absence of an injunction."
David Gandler, co-founder and CEO of Fubo, said in a statement that "today's ruling is a victory not only for Fubo but also for consumers."
"This decision will help ensure that consumers have access to a more competitive marketplace with multiple sports streaming options."
The three companies behind Venu Sports intend to appeal.
"We believe that Fubo's arguments are wrong on the facts and the law, and that Fubo has failed to prove it is legally entitled to a preliminary injunction," Disney-owned sports channel ESPN told AFP.
It added that its new platform would reach "a segment of viewers who currently are not served by existing subscription options."
Streaming platforms, which have proliferated in recent years, have recently begun combining to create offers meant to drive greater profitability.
One example is TV and internet giant Comcast's new StreamSaver package, which combines Peacock, Netflix and AppleTV+ for $15 per month -- a price 35 percent cheaper than buying each service separately.
Such alliances allow platforms to pool efforts at attracting users and advertisers, while also providing leverage in negotiating with content providers, particularly sports event organizers.
If Venu Sports is allowed to launch "it will be the only option on the market for those television consumers who want to spend their money on multiple live sports channels they love to watch, but not on superfluous entertainment channels they do not," Garnett said.
She also noted that Fubo has not yet reached profitability. If Venu Sports comes to fruition, she said, it would likely precipitate "a swift exodus of large numbers of Fubo's subscribers" as well as bring about bankruptcy for the company.
