A federal appeals court on Wednesday ordered new sentences for two former National Century executives convicted in a $1.9 billion corporate fraud case once likened to the Enron scandal, saying the government had proved some but not all of its case.

A three-judge panel of the 6th U.S. Circuit Court of Appeals in Cincinnati overturned Donald Ayers' conviction of conspiracy to commit money laundering, and Roger Faulkenberry's conviction of money laundering and conspiracy to commit money laundering, saying the government didn't provide enough proof.

Remaining in place are Ayers' convictions of conspiracy to defraud the U.S. and securities fraud, and Faulkenberry's convictions of conspiracy to defraud the U.S., securities fraud and wire fraud.

Ayers, 74, is serving 15 years in Coleman federal prison in Florida after his 2008 conviction with Faulkenberry and four other top executives from National Century Financial Enterprises, a Columbus health care financing company. Federal prosecutors compared the case to Enron.

Faulkenberry, 49, is serving 10 years in Gilmer federal prison in West Virginia after his 2008 conviction.

The court said the government didn't prove that advances Faulkenberry and Ayers made to medical companies were designed to conceal the money's source.

"Money in motion does not necessarily equal money laundering," Judge Raymond Kethledge wrote in Faulkenberry's case.

The Justice Department is reviewing the rulings, spokeswoman Laura Sweeney said.

It's unclear how the ruling will affect the men. Faulkenberry was originally serving the 10-year money-laundering sentence concurrently with his other five-year sentences. It's possible that a judge could order his remaining sentences run back to back and that he would still serve a 10-year sentence.

The same factors are true for Ayers, the court said.

National Century offered financing to small hospitals, nursing homes and other health care providers by buying their accounts receivable, usually for 80 or 90 cents on the dollar, so the providers wouldn't have to wait for insurance payments. National Century then collected the full amount of the payments.

Prosecutors said executives authorized millions in unsecured loans to the health care providers, then misled investors about the loans.

As the money owed to the company mounted, National Century declared bankruptcy in November 2002.

Ayers, of Fort Myers, Fla., was National Century's vice chairman, chief operating officer, director and owner.

Faulkenberry was National Century's director and vice president of securitizations and later executive vice president for client development.

Another company executive convicted at the same time, Rebecca Parrett, fled before sentencing and remains a fugitive.