United Airlines and US Airways are in very advanced talks and expect to announce within weeks that they are combining, two people familiar with the negotiations said yesterday.

Putting the two carriers together would create an airline that would jockey with a combined Delta-Northwest for the title of world's largest airline.

United and US Airways stepped up their talks after Continental Airlines caught United off-guard by deciding not to pursue a deal with the UAL Corp-owned carrier.

The two people familiar with the talks asked not to be named because of the sensitive nature of the discussions. The timing of any agreement remains hard to predict, and either side also could pursue an alliance instead or simply walk away from a deal, as Continental did.

Representatives of both airlines said they do not comment on rumours or speculation about consolidation.

Chicago-based United and Tempe, Arizona-based US Airways have been in preliminary talks for weeks about possibly teaming up, although United had focused more recently on joining with Continental.

As the second- and seventh-largest US airlines by traffic, both are under more competitive pressure to consolidate in the wake of the proposed creation of the Delta-Northwest mega-carrier.

Combined, the two have about 91,000 employees and annual revenues of $31.8bn (£15.9bn).

Other details of their talks were not immediately known, including what the name or headquarters location of the combined carrier would be. As a significantly larger airline, however, United typically would prevail in those decisions.- AP