Hertz has filed a defamation suit against Audit Integrity, a research firm that identified Hertz as one of 20 companies that has the highest probability of declaring bankruptcy among publicly traded firms with more than $1 billion market capitalizations.

In the complaint, Hertz claims that Audit Integrity and company CEO Jack Zwingli falsely said Hertz is "among the 20 major companies most likely to go bankrupt because there is fraud in Hertz’s financial reporting."

In a Sept. 16 news release announcing its general research results, Audit Integrity said, "Findings suggest that fraudulent accounting and poor governance impact bankruptcy risk in addition to more generally accepted factors such as measures of liquidity, leverage and profitability."

Zwingli is quoted as saying, "Market volatility and sudden downturns such as we have been experiencing must be factored into bankruptcy risk. Fraud also plays a part, especially when companies are faced with survival decisions. These are the toughest companies to identify because, on paper, they appear solvent. Our model uncovers the underlying fraud that can be behind seemingly healthy financial statements."

Audit Integrity gets more specific in a white paper published at its website, listing Hertz as having an AGR (accounting and governance risk) percentile of 17.

Audit Integrity said it devised AGR as a way to measure fraud-related risk. The lower the number, the higher the risk.

Of the travel companies on Audit Integrity's list of 20 companies most likely to declare bankruptcy, Las Vegas Sands had the lowest AGR score at 9. Others on the list were Continental Airlines with an AGR score of 16 and American Airlines at 25.

In its complaint, Hertz said Audit Integrity's report does not disclose the underlying facts or statistics to support that Hertz is "one of the 17% riskiest companies for corporate fraud."

The car rental company said Audit Integrity's publishing of "false and defamatory statements" have unjustly impaired Hertz's business and reputation.

Hertz is seeking an undetermined amount in damages, a retraction of Audit Integrity's findings and an apology.

The lawsuit was filed in a state court in New Jersey's Bergen County, where Hertz's headquarters is located. Audit Integrity has offices in New York and Los Angeles.