The credit rating for U.S. shale player Chesapeake Energy was downgraded because of cash flow problems in the weak market, Moody's said.

Moody's Investors Service downgraded the corporate rating for Chesapeake Energy Corp. by one notch to Ba2. Moody's Senior Vice President Pete Speer said the downgrade came as a result of weak cash flow and the toll taken by lower natural gas and crude oil prices.

"Chesapeake will have to execute on assets sales and other transactions to meaningfully reduce its debt levels to better align its capital structure with the current commodity price environment," he said in a statement.

Energy consultant group IHS warned the depressed crude oil market could limit the borrowing options for North American exploration and production companies like Chesapeake.

The company, which has headquarters in Oklahoma, said in a September filing with the Securities and Exchange Commission it was cutting 15 percent of its workforce, or around 750 employees. Explaining the layoffs, the company said it was aligning its workforce to the business environment brought on by the sustained slump in energy prices.

Moody's revised its overall forecast for Chesapeake from stable to negative. Trajectory moving into 2016 should continue to move lower for the shale company.

"The company's low cash flow generation will likely result in negative free cash flow in 2016," the ratings agency said. "Moody's expects the company's capital spending in 2016 to be lower than 2015, resulting in declining production volumes and reserves in 2016 as capital spending will fall below maintenance levels."