Lloyd's underwriter Goshawk Syndicate Management is to sue the company behind the US version of Who Wants To Be A Millionaire?
Goshawk, a subsidiary of Goshawk Insurance Holdings, has started legal proceedings in London against Buena Vista Entertainment.
It is believed Goshawk wants to end its contract with Buena Vista because it has had to pay out too much money to winning contestants on the TV show.
In the US version of the programme - adapted from the British original - two people have won $1 million while three others have scooped $500,000.
Goshawk said the proceedings have been issued by itself "and a number of other insurers in connection with a contingency insurance dispute".
The dispute refers only to the third series of the programme. The underwriter was not involved in the insurance arrangements, or any claims arising from, the previous two series.
It also has no involvement in the British show presented by Chris Tarrant, where the highest payout so far has been £500,000 to one lucky winner.
Goshawk said that its maximum exposure under the disputed insurance cover would have been around £750,000. A substantial part of this sum would be protected by its own normal reinsurance arrangements.
The syndicate specialises in contingency insurance and writes a wide range of this type of business. Its statement added: "Disputes do arise on coverage issues in the normal course of insurance business. However, the group does not expect to comment in detail on such occasional disputes."