Moody's has lowered the senior debt rating of Marsh & McLennan (MMC) from A3 to Baa2.
The ratings remain under review for possible further downgrade.
The downgrading follows the announcement of a series of practice reforms at Marsh.
The ratings agency said the MMC reforms signal reduced financial flexibility coming from its lower earnings capacity and the financial impact incurred by the firm in restructuring its business model.
Moody's also said doubts still linger over the size of potential fines and potential litigation settlements arising from the Spitzer investigation.
