United and American match BA's bonus offer to the U.K.

Now when you fly on American or United out of Calgary and connect via their U.S. hubs to the U.K. you can earn up to 50,000 bonus miles in their respective frequent flyer programs until June 30, 09

For American, flights to London (LHR) or Manchester (MAN) qualify and for United it is only for flights to London (LHR).

For American AAdvantage you'll earn:
50 ,000 Bonus Miles for First/Business Class (booked in F, J, A, D or I)
25,000 Bonus Miles for Select Economy Class fares (booked in R, Y, B or H)

For United Mileage Plus:
50,000 miles for United First (F, A, P booking class) or United Business (C, D, Z booking class)
25,000 miles for United Economy (Y, B, M booking class)

See more information and the registration links (you are required to register for the offers) click on the following links
American AAdvantage
United Mileage Plus