Paddy:
ATI gives the following 2005 results:
Airline.....Net profit/loss United.....-$21bn
Delta.....-$3.8bn
Northwest.....-$2.5bn
AMR (American).....-$861m
(Continental.....-$68m)
Note these are net losses, not operating losses, so in several cases (especially United's

) they include one-off bankruptcy/restructuring costs.
More detail available from the individual carriers' websites.
Cheers
C.