Calpine put its bankruptcy reorganization plan on hold on Friday to weigh alternative plans presented to the independent power producer.
Calpine, in a filing at the U.S. Securities and Exchange Commission, said "certain parties" have contacted the company about an alternative reorganization that would guarantee a payout to creditors.
The filing did not identify the parties and Calpine spokesman Mel Scott declined to elaborate.
A person familiar with the bankruptcy proceedings, however, told Reuters that Calpine has received proposals from several financial and energy companies in the last few weeks, who have offered to buy enough equity in Calpine to pay off unsecured creditors in full in cash.
A mix of financial sponsors and energy industry players could potentially combine and wind up controlling the company.
Evaluation of the proposals is expected to move quickly in the next two weeks.
Hedge funds like Appaloosa Management, which is the biggest shareholder of bankrupt auto parts maker Dana, have grown more active in taking controlling stakes in distressed companies.
The Calpine filing said it "decided to take a brief period of time to investigate the possibility of an alternative plan structure offering guaranteed recoveries to stakeholders, which potentially could offer recoveries that are superior" to its current plan.
Calpine was working with investment banker Miller Buckfire "to gauge potential investors' interest" in sponsoring a guaranteed distribution plan, according to the filing.
Such a plan "would not compromise" Calpine's balance sheet on emergence from bankruptcy, the company said.
A Miller Buckfire spokesman was unavailable for comment.
Calpine said in its filing that to allow time to evaluate an alternative plan, it asked the U.S. Bankruptcy Court for the Southern District of New York to move back an Aug. 8 hearing on its bankruptcy disclosure statement to Sept 11.
Calpine also asked for final commitment letters from potential plan sponsors to be submitted by Aug. 16.
San Jose, California-based Calpine filed a reorganization plan at the court on June 20 that valued the company at about $20.3 billion.
The plan said unsecured creditors may receive nearly all of their allowed claims and current shareholders could receive about $1.80 a share.