BAE is the UK partner in the Eurofighter project

The two companies have cooperated on a series of programmes, but there are no plans for closer ties, said Boeing chief executive Harry Stonecipher.

He said BAE had a range of activities the US firm was not interested in, such as ship and submarine building.

His comments contrast with the apparent enthusiasm for a merger from his predecessor, Phil Condit.

BAE SYSTEMS UK's biggest defence contractor Looking for US merger partner Owner of 20% stake in plane maker Airbus BAE Systems share price

Mr Stonecipher, in London for his first visit since his appointment as new Boeing boss, said he would be meeting BAE chairman Sir Richard Evans but purely for social reasons.

Last week, Boeing and BAE were turned down by the UK government over a joint bid for a huge contract to provide the Royal Air Force with refuelling aircraft, preferring the pan-European EADS group.

There has been persistent speculation about a US tie-up for the UK's biggest defence firm.

Some investors have argued that finding a US merger partner is crucial if BAE is significantly to expand its business in the valuable US market.

In October US firm General Dynamics walked away from exploratory merger talks with BAE.