Marsh is understood to be at the centre of a major claim following a plane crash which killed nearly 100 people in Indonesia.
The broker is thought to have placed business for the airline, Adam Air, which saw one of its passenger planes go missing en route from Surabaya, in Java, to Manado on New Year's Day.
Marsh is also understood to have placed cover for the aircraft's manufacturers, Boeing, and its engine manufacturer, General Electric.
It is believed Marsh placed the business within aviation syndicates at Lloyd's.
Mystery surrounds the cause of the plane's disappearance, but it is widely believed that a mayday call was issued from the 17-year-old Boeing 737-400 while it was in cruise, typically the safest part of the flight.
As Insurance Times went to press the missing jet, flight KI-574, had still not been located.
Last year, one of the Adam Air's jetliners lost all communication and navigation systems for four hours during a flight between the Indonesian capital Jakarta and Makassar on Sulawesi Island, forcing the pilot to make an emergency landing.
