Marsh & McLennan (MMC) has suffered a $US210 million ($223 million) first-quarter loss following a massive $US425 million ($452 million) writedown on its struggling risk consulting business Kroll.

Newly installed MMC President and CEO Brian Duperrault has acted swiftly to restructure the company’s under-performing divisions by slashing 300 jobs at Guy Carpenter and offloading Kroll’s mortgage lending and government services businesses.

Mr Duperrault is also taking the “non-core” corporate advisory and restructuring operations out of Kroll’s orbit to create a separate business within MMC’s risk consulting and technology division.

The world’s largest broking group delivered an 8% lift in consolidated revenue, to $US3 billion ($3.2 billion), driven by a strong performance from its flagship broker Marsh and consulting operation Mercer.