The four-nation Airbus consortium is favourite to win a pounds 3bn order for up to 100 short-haul jets to enter service on BA's regional European routes.
As a consolation, the airline looks like selecting the twin-engined Boeing 777 for a long-haul jet order worth up to pounds 2bn. The purchase could also bring in engine orders worth up to pounds 500m for Rolls-Royce.
BA may confirm the giant orders at the Farnborough Air Show next month, but airline sources indicated yesterday that there might be an earlier announcement.
BA is expected to order about 60 aircraft from the Airbus A320 range both for the main airline and its European subsidiaries, Deutsche BA and Air Liberte. Options are likely on a further 60 aircraft.
This would be the first time BA has bought direct from Airbus and a major coup for the consortium in which British Aerospace has a 20 per cent stake. The aircraft will be powered by either V2500 engines from the International Aero Engines consortium, in which Rolls has a 30 per cent stake, or by the CFM56 of General Electric and Snecma.
The order for 777s could involve up to 30 aircraft. If Rolls is selected as the engine supplier, it would be a double bonus. BA's existing fleet of 777s are powered by GE90 engines. It has 18 in service and a further 11 on order.
When the order was placed seven years ago, Lord King, then BA chairman, controversially decided to opt for an American-powered aircraft to meet its future wide-bodied needs rather than a British-powered Airbus, the A330.
As a result BA is one of the few leading airlines which has no Rolls- Royce Trent engines in service. Selecting Rolls would mean that BA's fleet of 777s would be powered by two different engines.
Industry sources said BA could still justify this on economic grounds since the latest versions of the Trent have greater power and thrust than competing engines, extending the range and payload of the new 777s.