About 250 of the world's biggest companies have sought to postpone a trial involving 8,000 asbestos claims.

The defendant companies want the US Supreme Court to postpone the case, due to be heard in West Virginia on 23 September, arguing that the case should be heard by a federal court.

If the companies lose, it is estimated insurers will face losses of more than $200bn (£128bn) in the next 20 years.