FIN 48, the Financial Accounting Standards Board’s recently published guidance on the accounting of uncertain tax positions could provide credit-rating analysts and investors with clues about how companies “may be using taxes as an earnings management tool,” according to an executive at Moody’s Investors Service.

To be sure, tax exposures unearthed via the new guidance are unlikely by themselves to push credit ratings down, the rating agency said in a report on the new standard. But they could add to downward pressure on ratings.

“We believe the greatest benefit of FIN 48 for analysts and investors will be to improve the disclosure of tax reserves,” said Moody’s vice president and senior credit officer Mark LaMonte. “The disclosures that FIN 48 requires will provide incremental insight into a company’s exposure to aggressive positions taken on its tax returns and, potentially, how the company may be using taxes as an earnings management tool.”

The new disclosures under the rule, which goes into effect in the quarter ending March 31, 2007 for calendar-year companies, will include a tabular roll-forward of a company’s reserves for uncertain tax positions.

The standard will help supply analysts with insight into cases in which there are significant divides among companies statutory, effective, or cash tax rates and situations when material tax contingencies have been revealed, according to the Moody’s report.

The rating agency contends that since current practice for uncertain tax positions is varied and disclosure is cloudy, hefty cash liabilities from tax positions are prone to crop up with little warning.