Aon Corp., the world’s second-largest insurance broker, is about to settle fraud investigations by New York Attorney General Eliot Spitzer and the two other states for $190 million, people familiar with the matter said.

The agreement would put an end to investigations by New York, Connecticut and Illinois into fees that Spitzer said were equivalent to the payments received from insurers.

The decision on reaching compromise would also help reassure investors in Chicago-based Aon to succeed founder Patrick Ryan as a new chief executive officer.

Both parties Aon and Spitzer refused to comment on the matter.

In January Spitzer settled with Aon’s bigger rival, Marsh&McLennan Cos. for $850 million. In his lawsuit against Marsh, Spitzer said that fees from insurers prompted brokers to steer clients to insurers that paid the most. New York-based Marsh earned $845 million of fees from insurers in 2003 and according to Spitzer Marsh’s settlement corresponded to that amount.

Aon would be the first broker to reach settlement with Connecticut and Illinois since Marsh managed to settle only with New York and still handles a huge amount of new investigations followed by Spitzer’s suit.

Spitzer’s Marsh suit had a negative impact on Aon as well since shares fell 13 percent, and the company still faces difficulties in retaining clients and recovering from lost fee revenue.