LAWYERS acting for the insurers of the failed Pan American airline next month will ask a Scottish court to rule quickly on a claim of more than (pounds) 600m in losses incurred by the company following the Lockerbie bombing.

In what may be one of the largest damages claims in Scotland, aviation underwriters of the firm, which filed for bankruptcy in 1991, are claiming Abdelbaset Ali Mohmed al Megrahi, the convicted bomber, and the Libyan state are liable for damages of (pounds) 192m, plus interest, for the loss of the aircraft and other financial losses incurred.

The legal team has lodged a motion for summary decree at the Court of Session, arguing that there is no defence and that Megrahi's conviction at Camp Zeist in the Netherlands in 2001 proves liability. It wants the claim to be settled without a full hearing.

It is also expected to raise an action against Libyan Arab airlines, for whom Megrahi worked, and Al-Amin Khalifa Fhimah, who was acquitted at Camp Zeist.

Libya is vehemently defending the action and denying all involvement, despite the fact that Tripoli has accepted some responsibility for the atrocity and agreed to pay record levels of compensation to the relatives of those who died.

Megrahi, serving a life sentence in Barlinnie prison, has consistently denied all responsibility for the bombing. He is awaiting a decision from the Scottish Criminal Cases Review Commission (SCCRC) after applying for the right for a fresh appeal.

A team of Scottish lawyers is planning a robust defence to the civil action based on the grounds that the conviction was unsound and that there is a continuing investigation into the case by Megrahi's lawyers and the SCCRC.

Lawyers acting on behalf of Libya are expected to claim that any civil action would prejudice the hope for a criminal appeal and would be premature on the grounds that Megrahi could have his conviction overturned.

In the lawsuit following the 1988 terrorist bombing of PanAm Flight 103 over Lockerbie, which killed 270 people, the victims' families proved that the airline acted with wilful misconduct, and Pan Am's insurers were forced to pay out more than (pounds) 282m.

A New York Federal jury ruled in 1992 that PanAm had been guilty of wilful misconduct because it had repeatedly ignored warnings that its baggage-security system was inadequate.

Lawyers acting on behalf of the aviation underwriters subsequently lodged a civil action for more than (pounds) 168m against Megrahi and the Libyan state in the early 1990s, on the grounds that countries do not have the right to sovereign immunity under Scots law.

The action was suspendedbecause of the emergence of criminal proceedings against Megrahi and Fhimah. If the civil action now goes ahead, it would be the highest litigation claim in Scotland, exceeding the amount paid following the Piper Alpha gas platform explosion on the North Sea in 1988.

The Piper Alpha case was brought to decide whether sub-contractors should contribute towards the (pounds) 140m damages that the platform's operators had paid to survivors and victims' families. The action called for (pounds) 82m which, doubled by interest, was settled in 2002.

Eddie Mackechnie, the lawyer for Megrahi, said the main issue was to prove Megrahi's innocence.

Patrick Slomski of Beaumont and Sons solicitors in London, who is acting for the insurers, declined to comment.