America's largest owner of local sports channels filed for bankruptcy after its efforts to pivot its business model were stymied by its unwieldy balance sheet.

Diamond Sports Group, which operates under the Bally Sports brand, sought Chapter 11 court protection on Tuesday in Texas. It marks a remarkably swift downfall for the Sinclair Broadcast Group-owned company, which loaded up on debt to buy 21 regional sports networks from Walt Disney Co. in 2019 for $9.6 billion.