A decision on whether the Lockerbie bomber is to be transferred to Libya will be taken on "judicial grounds alone", the First Minister said.

The Libyan authorities submitted a request on Wednesday for the transfer of Abdelbaset Ali Mohmed al Megrahi. The 57-year-old - who has been diagnosed with prostrate cancer - is currently serving a life term in Greenock prison for the 1988 bombing that killed 270 people.

The second appeal against conviction by Megrahi began in Edinburgh last week, but this must be dropped if his transfer to a Libyan jail is to take place.

Alex Salmond, speaking during First Minister's Questions on Thursday, said it would have been "greatly to be preferred if the judicial processes of Scotland" were allowed to take their course.

But Mr Salmond insisted that the decision on the prisoner transfer - which will be considered by Justice Secretary Kenny MacAskill - would be based solely on judicial grounds.

Mr Salmond stressed: "What I have said throughout this process is that everything we do as a government will uphold the integrity of the Scottish judicial system.

"Let me repeat that today and also say the decision made by the Justice Secretary will not be made on economic grounds or on political grounds; it will be made on judicial grounds and judicial grounds alone."

The issue had been raised by Scottish Liberal Democrat leader Tavish Scott, who said that he believed that "al Megrahi should serve his sentence in Scotland".

And the Lib Dem recalled a statement Mr Salmond had made to Holyrood in June 2007, when he said that Scottish law officers and others, including the Secretary General of the UN, had given assurances that any sentence that was imposed would be served in Scotland.

Mr Scott then asked Mr Salmond: "Does he stand by that statement he made as First Minister?"

Presiding Officer Alex Fergusson told MSPs that any discussion on the Lockerbie bomber should not stray into the appeal or whether he is guilty or innocent.

Labour MSP Elaine Murray, member for Dumfries, asked what consideration had been given to the possible transfer of Megrahi to Libya.

Ms Murray said comments had already been made by the First Minister that anyone connected to the bombing should be excluded from prisoner transfer.

"Do these statements indicate that Scottish ministers have actually predetermined their response to the Libyan Government, and if so does this enable the Libyans to seek judicial review if the request is turned down?" she asked.

Mr Salmond insisted no decision has been made and added: "I think we were absolutely right - demonstrably right - to warn of the possible consequences of the sequence of events set in place in June 2007, just as we are absolutely duty bound to consider a prisoner transfer agreement on its merits.

"Given the relevant legislation, there can be no prejudging of that agreement before such a PTA came into place."

A treaty between Britain and Libya allows for the transfer of prisoners. No decision can be made by the Scottish Government if there are unfinished legal proceedings, but this proviso does not prevent Libya from making an application.