Video rental giant Blockbuster is expected to file for Chapter 11 bankruptcy protection as early as today, the Wall Street Journal reported Wednesday, citing sources.

Investor Carl Icahn, who owns about a third of the firm's senior debt, is playing a key role. He has led the charge to free Blockbuster of debt and will either return to the company's board himself or designate a representative, the paper said.

Depending on how quickly final details get ironed out, the Chapter 11 filing - which allows a company to continue operation unlike a Chapter 7 liquidation - could come today, later this week or next week, the Journal said.

Blockbuster has been working with senior creditors on details of a bankruptcy restructuring plan to get them on board ahead of the filing. Those creditors would convert the Blockbuster debt they hold into ownership stakes in the company, while lower-ranking creditors would lose their holdings, according to the Journal.

Blockbuster couldn't immediately be reached for comment.