The appeal by dying former Libyan agent Abdel Basset al-Megrahi against his life sentence for the 1988 Lockerbie aircraft bombing, will not be decided until next year.

Lord Hamilton today told the Scottish Appeal Court at the end of a two-day procedural hearing that the final two substantive appeal sessions would run from November 2 to December 11, and January 12 to February 26, 2010.

A total of 270 people were killed when the Pan Am jumbo jet exploded over Lockerbie.

One of the five judges hearing the appeal is recovering from recent heart surgery and Lord Hamilton said this, combined with the pressure of other business on the court, meant it was not practical to hold earlier sessions.

The illness of Lord Wheatley has already meant a deferment in considering appeal arguments heard so far, and Megrahi's lawyer Maggie Scott expressed dismay at the delays.

Yesterday she said: "There is a very serious danger that my client will die before the case is determined."

She added his health "is deteriorating with a relentless onset of symptoms".

Megrahi, 57, has terminal prostate cancer and is currently in Greenock prison.

After a trial in a special Scottish court meeting in The Netherlands in 2001, he was sentenced to 27 years' in prison.

An appeal the following year was rejected, but a review gave the go-ahead in 2007 for a second appeal on the grounds that there may have been a miscarriage of justice.

In the first part of the appeal through May, his lawyers questioned whether the trial court had been correct in accepting evidence relating to his identification, the type of fuse in the bomb and how it was consigned to the Pan Am flight.

In the next hearings, legal sources said the appeal lawyers were expected to introduce fresh evidence and question the competence of his previous lawyers.

The Libyan and British governments signed a prisoner transfer agreement this year and Tripoli has sought Megrahi's return.

Scotland's Justice Minister Kenny MacAskill is currently consulting all parties concerned, including the US and Libyan governments and families of the victims of the bombing before deciding whether to accede to Libya's request.