No doubt about it - the aircraft has been a hugely profitable operation for both airlines.
As Raptor posted, B.A were bailed out by the taxpayer shortly after the fleet was purchased. After that moment in time, the aircraft has operated at a very high profit margin, with an average of 90% load factors.
In the same vein, it's an open secret that Air France have always been propped up by one of the French governments, and their fleet operated in a similar fashion.
The aircraft makers may have made a "paper loss" on the venture, but again, it was so heavily subsidised with deals and murky counter deals, it's difficult to quantify any actual profits or otherwise.
All said, it appears that the European taxpayer carried the cost of development and initial operation, and B.A and Air France board members and shareholders have subsequently seen the benefit.