A banner with the logo of streaming service Fubo TV hangs outside the New York Stock Exchange.

Streaming service Fubo would have faced certain financial ruin if two of its programming partners were allowed to move forward with the launch of a similar sports-inclusive streaming service, according to comments made in open court by the company’s chief executive.

At a court hearing earlier this year, Fubo CEO David Gandler warned that the service, called Venu Sports, would cause it to lose hundreds of thousands of customers — or nearly 30 percent of its current subscriber base — which would have resulted in a loss of tens of millions of dollars in revenue before the end of the year.

That outcome would have resulted in Fubo’s stock price dipping to historic levels, to the point where it faced the potential of being delisted from the New York Stock Exchange, according to court...