Ratings agency Moody's announced it had changed the outlook on Marsh & McLennan's A2 senior debt rating from stable to negative.
Moody's said it considered the allegations of corruption brought by the New York attorney general Eliot Spitzer to be “serious”.
Yet, it said, it was not possible to determine whether, or how severely, the ongoing investigations would affect the company.
The ratings company said Marsh & McLennan's position would look less severe if additional complaints were made against other participants.
