Aon said it is negotiating with lenders to access $890m in credit should Spitzer choose the company as his next target, according to reports today.
Aon records have already been subpoenaed by the New York attorney general, and it is under investigation by several other states.
The company's market value has dropped by 25% since the investigation into bid-rigging at Marsh was announced.
Aon chief executive Patrick Ryan said an internal investigation has not yet discovered any activity similar to the bid-rigging found at Marsh.
