Plane maker Airbus has warned that airlines face further delays in receiving the A380 superjumbo.
More time and resources were needed to increase production, the company said, which would result in fewer deliveries than planned during 2008 and 2009.
Earlier this month, two airlines revealed that Airbus had warned them of possible further delays.
Deliveries of the A380 are already running almost two years late because of delays centred on wiring problems.
The company said the latest delays were due to problems moving from the initial production phase, responsible for the first 25 aircraft, to a more intensive production line.
No details were given about the financial implications of the announcement.
"The extent of the additional costs will be influenced by the actual production and delivery scenario," Airbus said.
Airbus - which is part of aerospace group EADS - now plans to deliver 12 planes this year, instead of the 13 expected.
In 2009, 21 A380s will be supplied to carriers against the previous plan to deliver 25.
Deliveries for 2010 would be discussed with airlines in the coming weeks, Airbus added.
The first A380 entered commercial service last year with Singapore Airlines, while Emirates is the plane's largest customer.
EADS said that four A380s have been delivered as planned, while a further 17 were in various stages of production.
Both Dubai-based Emirates and Abu Dhabi-based Etihad Airways said earlier this month they had received warning of delays.
British Airways has ordered 12 A380s, due to be delivered from 2012, while Virgin Atlantic has ordered six, to arrive from 2013.
The airliner's wings are made at Broughton in north Wales and at Filton in Bristol.