The merger, which was scheduled to complete by the end of the first quarter, has been delayed by days as both airlines attempt to resolve some minor differences in the agreement.
Iberia said that the delay in no way indicated that the merger was under threat, while BA said that the delay was not related to the recent work stoppage launched by staff.
BA said: “We will not sign the merger agreement with Iberia in the first quarter of 2010. This is due to technical issues that need to be resolved and we anticipate that the agreement will be signed in due course.”
The news comes as the airline said yesterday that it flew 80 per cent of customers booked for travel during the work stoppage period that was launched by cabin crew.
The airline flew 192,000 passengers during the strike period out of the 240,000 scheduled to travel.
Yesterday, BA chief executive Willie Walsh said Unite, the union representing the striking crew, had failed to ground the carrier.
“We have seen a fantastic effort by dedicated staff across British Airways to keep the flag flying,” said Walsh.
“We do not want this dispute to go on. I believe that we could resolve this dispute very quickly,” said Walsh.