Ed James of Price Waterhouse, the receivers, said the talks had been constructive and further negotiations would now take place. The delay in concluding the negotiations, however, could mean Swan will be too late to accept a pounds 6m Ministry of Defence tanker refit order for the RFA Olwen.
The deadline for accepting the Olwen contract is Wednesday and the ministry has said Swan Hunter will be given the work only if agreement is reached on the sale of the yard.
Hopes for the future of Swan faded last month when the Government awarded a much larger contract for the refit of the Sir Bedivere to the rival Rosyth yard. Since then CMN, which is the only interested buyer, has offered half the original pounds 10m price-tag on the yard. The receivers have lowered that to pounds 7.5m but there still appears to be a significant difference between the sides.
Price Waterhouse believes that unless CMN increases its offer above pounds 5m, there would be more to gain from selling off the assets.
In a joint statement, Mr James and Iskandar Safa, head of CMN's parent company Soffia, said: 'We have been able to discuss at length some of the major issues, but further discussions are necessary and will need to involve other parties.
'The whole issue is a very complex one and we still have some way to go to discover if an agreement is possible.'
The loss of the Olwen raises a question over the future of more than 200 workers who are temporarily laid off.
The Olwen was always viewed as a stopgap, however, until work on the Sir Bedivere could begin, rather than as a lifeline in itself. Without the Sir Bedivere contract, work will run out in November for the 650 people still working at the yard.