The Lockerbie bombing claimed the lives of 270 people
A decision on the appeal by the man convicted of the Lockerbie bombing will not be made until the autumn after a judge underwent heart surgery.
Lord Wheatley is expected to resume judicial duties in mid-September.
The Appeal Court said a verdict could not have been reached this week even if the judge had been fully fit.
A statement said a "reasoned decision" on Abdelbaset Ali al Megrahi's appeal could not now be expected until some time in the autumn.
Lord Justice General Lord Hamilton said Lord Wheatley had recently undergone successful surgery.
However, he added that his period of recuperation could be protracted.
"The expectation is that he will be fit to resume judicial duties about the middle of September, though it may be sooner," he said.
He said "significant work" had been done on the case prior to Lord Wheatley's admission to hospital.
He added that there were still "complex and difficult issues" which needed to be resolved.
"There is no way in which the necessary consultation and resolution could have been completed by today's date, even if Lord Wheatley had been fully fit," said Lord Hamilton.
Jim Swire has called for Megrahi to be released while his appeal continues
"His indisposition, however, complicates matters."
He added that the court recognised that Megrahi - who has prostate cancer - was anxious to have a decision on parts of his appeal as soon as possible.
"Regrettably, the court is unable to accommodate that," he said.
"It is only when Lord Wheatley is fit to resume judicial duties that it will be possible to resume consultation among all the judges with a view to reaching a final decision."
Defence QC Maggie Scott expressed "dismay" at the delay.
She said: "Of course I acknowledge the unfortunate and unexpected circumstances behind it.
"There is a very real risk my client will die before this case is adjudicated.
"He is deteriorating and there is a relentless onset of symptoms."
Earlier this week, Justice Secretary Kenny MacAskill met Libyan government officials to discuss their bid to have the Lockerbie bomber transferred from Scotland.
It was part of the "ongoing process" of considering their application to have him serve the rest of his sentence in a Libyan jail.