The company, which entered Georgia's gas market two years ago, filed Wednesday after losing both its credit line and its contracted fuel supply this week.
Georgia utility regulators will begin deciding today if Catalyst can continue to sell gas in the state.
State law requires marketers to have enough credit to pay for the gas they order.
Catalyst Chief Executive Officer Fernando de Aguero said his company's bankruptcy stems from the meltdown on Wall Street.
The company has 30,000 customers in Georgia and liabilities of $20 million
"We are all aware of what's happening with the macro economy," he said. "And it's gone down into the midmarket and now Main Street.
"It's very common. It's going on all over the country right now."
Catalyst's credit line and gas supply contracts were both with Constellation Energy, the nation's largest independent energy marketer. Constellation was a trading partner of Lehman Brothers, and its stock price collapsed with the fall of Lehman Brothers' two weeks ago.
Constellation cut off Catalyst late last week, leaving the company scrambling for credit.
The state Public Service Commission can suspend Catalyst's license and send its customers to other marketers. It's not yet clear whether the authority of bankruptcy court will supersede the regulators.
Mr. de Aguero and the company's vice president for regulatory affairs, Steve Moore, both said the company will work with the PSC to guarantee its customers get service.
GAS SUPPLY SET TO RISE FOR WINTER
WASHINGTON --- Despite supply interruptions caused by Hurricane Gustav, there should be plenty of natural gas available for heating this winter and prices are likely to stay about the same as last winter, natural gas producers said Thursday.
Nearly half of the natural gas production in the Gulf of Mexico remains shut down because of two recent hurricanes. But the industry said gas inventories at the start of the heating season -- traditionally November -- are expected to be well above the five-year average.
And this winter producers are expected to pump about 8 percent more gas than last winter, with more wells operating, said the Natural Gas Supply Association.
-- Associated Press