Facing a likely bankruptcy, Sirius XM Radio Inc. found a savior in Liberty Media Corp., which will lend $530 million to the satellite radio provider and block a bid for control that had been waged by a rival both companies share: Dish Network Corp. CEO Charlie Ergen.

Sirius had warned it could file for bankruptcy as early as Tuesday if it could not successfully negotiate with its debt holders.

Sirius XM Radio has 20 million subscribers who use the service to listen to sports, music and talk, including Howard Stern’s show, which Sirius landed with a five-year, $500 million contract that could have been terminated in a bankruptcy.

The company found itself on the brink as credit markets dried up and auto sales plunged — a critical factor for Sirius because many new subscribers buy the service in package offers with cars and trucks.