A week after announcing the closure of a fifth of its stores. in the U.S., the struggling retailer succumbed to the inevitable and filed for bankruptcy protection.

This just weeks before the start of the holiday shopping season. A bleak portent for the retail sector.

“Despite aggressive efforts to secure vendor support, vendor concerns about the company’s liquidity and ability to pay for its purchases in this difficult economic climate have escalated considerably,” the company said in a statement. “Faced with the need to secure ongoing vendor support and to ensure adequate merchandise flow to stores during the important holiday season, the company has determined that it would be in the best interest of its stakeholders to file for reorganization relief under Chapter 11.”

BlockBuster must be thanking its lucky stars it chose to abandon its $1.3 billion gambit for the foundering electronics chain….