For the fourth time in nearly a year, British Airways will increase ticket prices to cover the increase in its fuel costs, expected to reach 1.6 billion pounds in the current financial year, 450 million pounds more than in 2004-2005.

As from Monday, British Airways will increase the fuel surcharge from 24 to 36 pounds (36 euros, 43.5 dollars) on long-haul flights.

"A new increase is unhappily inevitable," said BA's commercial director, Martin George.

The oil price increase past the 60-dollar mark in New York this week has had an immediate effect on the bottom line of the airlines, for which fuel represents about 20 percent of their overall costs.

Several other carriers moved immediately to introduce or increase surcharges.

Virgin Atlantic said it would increase surcharges from 24 to 36 pounds. The freight division of Lufthansa was expected to announce a price hike on Monday. The low cost German carrier Germanwings said it would introduce a fuel surcharge of three euros for the first time on all its tickets.

Air France-KLM, which announced fare increases in March, was hesitating to slap on fresh surcharges having done so three times already since May 2004.

The alliance has hedged 81 percent of fuel price increases above 45 dollars a barrel for 2005 and 2006 and said there were no plans for the time being to hike long-haul surcharges beyond the present 34 dollars.

In 2004-2005, Air France-KLM took in 300 million euros in surcharges for a total fuel bill of 2.65 billion euros, which is expected to increase this year to 3.37 billion euros.

Airlines hesitate to keep increasing surcharges because of the risk of losing passengers at a time when the industry is struggling to recover after three years of crisis.

"We have to reach the point where an important proportion of the surcharge should be offset by a reduction in fares, even if modest" to encourage ticket sales, said airline analyst Andrew David Lobbenberg of ABN Amro.