A judge issued a preliminary injunction against Disney, Fox and Warner Bros. Discovery on Friday over a planned sports-focused streaming service from the companies, saying the joint venture would most likely make the market for sports viewership less competitive.

The 69-page ruling from a federal judge in New York’s Southern District effectively halts — at least for the moment — the companies’ ambitious plans for the service, called Venu, which was aimed at sports fans who had abandoned cable television.

The service, which had been expected to become available this fall and cost $42.99 a month, promised to offer marquee games from the National Football League, National Basketball Association and Major League Baseball.

But the idea raised alarms with rivals, most notably a sports streaming service called Fubo that sued to block new service’s formation after it was announced this year. In a statement accompanying its complaint, filed on Feb. 20, Fubo alleged that Disney, Fox and Warner Bros. had “engaged in a long-running pattern” of trying to stymie its business through anticompetitive tactics.

The complaint led to a hearing this month that focused on whether Fubo should be able to obtain a preliminary injunction against Venu, essentially stopping the sports-media venture from proceeding.

In her ruling, Judge Margaret Garnett said Fubo was likely to prevail in its claim that the new service would “substantially lessen competition and restrain trade.” She added that refusing to grant the injunction could limit the effectiveness of any court order reached after a trial.