BA has 284 planes in its fleet

The UK airline said it was initially looking to buy 34 planes, with analysts estimating the airline would ultimately spend at least $7bn (�3.7bn).

BA, which said it planned to place the orders next year, said it was considering Airbus' troubled A380.

The A380 superjumbo is running two years late after high-profile problems.

BA said other aircraft it was looking at were Airbus's A330 and A350, and Boeing's 787, 777 and 747-8.

It is also inviting engine-makers such as Rolls-Royce and General Electric to bid.

Pension issue

"For the past four years, we have grown capacity by using our aircraft more efficiently," said BA chief executive Willie Walsh.

BA says it will consider the troubled A380

"In order to continue to grow our long-haul business we now need additional long-haul aircraft."

Mr Walsh added that it was vital for BA to cut its �2.1bn pension deficit before it started ordering the new aircraft.

He repeated that he was confident the firm would reach a deal with staff by next month.

BA has 284 planes in its fleet, of which 114 are long-haul planes - some of which are up to 17 years old.

Delays to the Airbus 380 have been caused by wiring problems.