Marsh & McLennan Cos., the world’s largest insurance broker, that has just started an investigation into its business practices with insurers, on Tuesday reported a $676 million fourth-quarter net loss related to restructuring and legal settlements.

The loss of $1.28 a share is compared to net income of $375 million, or 69 cents, a year earlier.

Chief Executive Officer Michael Cherkasky ``is doing a lot of the right things, but it’s not an issue that gets cleaned up right away,’’ said James Huguet, who owns $1.4 billion at Great Companies LLC, before Marsh results were released. Great Companies, based in Clearwater, Florida, sold its Marsh shares last year.