High oil prices have forced British Airways to increase the fuel surcharge on long-haul flights, the airlines owner International Consolidated Airlines (IAG) said today.Passengers travelling on world traveller flights in economy class will now have to stump another £10 a flight. That takes the surcharge up to £95 for flights of less than nine hours and to £116.50 for longer flights. On first class flights, the surcharge will rise by £20, to £125 on long-haul flights of less than nine hours and to £145 on longer flights.The announcement comes the day after oil prices hit a two-and-a-half year high above $120 a barrel as the war in Libya continues."Fuel now represents over one third of our costs and particularly affects our longhaul flights," said British Airways chief financial officer Nick Swift. "We are very aware of the wider economic pressures on our customers at the moment and we will bear the vast majority of the recent fuel price rise ourselves to keep this increase in surcharge to a minimum."British Airways and Spanish rival Iberia merged to form IAG last year.RG