The 2011-2012 downgrades by Standard & Poor's, Moody's and Fitch resulted in a sharp increase in Italy's risk indicators and contributed to a rise in its borrowing costs, forcing then-premier Silvio Berlusconi to resign.
A technocrat cabinet replaced him that enacted a series of tough austerity measures to stave off the threat of a default on Italy's massive sovereign debt.
Audit court said the probe was at a preliminary stage, however, and might be shelved and that it was premature to talk of suing for damages.
"It is still a preliminary investigation, therefore the case could also be thrown out, after (credit rating) agencies present their explanations and counter-observations," auditors said in a statement.
The court's statement came after the London-based Financial Times reported on Tuesday that it could be about to sue Standard & Poor's, Moody's and Fitch for 234 billion euros over the downgrades.
The FT said S&P had revealed that it had been notified that the Audit Court might present a claim, partly because the agency allegedly failed to account for Italy's cultural heritage when downgrading the country's rating.
"S&P never in its ratings pointed out Italy's history, art or landscape which, as universally recognised, are the basis of its economic strength," the FT quoted the petition as saying.
S&P dismissed the claim as "frivolous and without merit", the FT said.
Italian economy minister Fabrizio Saccomanni on Wednesday declined to comment on the reports of a possible state lawsuit against the ratings agencies, which he said wielded undue influence.
"I believe that today we measure the evaluation that investors give Italy more on treasury-bond interest rates which are falling to very low levels, and by the interest investors have in our privatisation and market-opening activities," he stated.
The minister made the remarks at a conference in the southern city of Naples' Federico II University.