The world’s airlines have probably hit the peak of the profit cycle after nine years of growth and amid concerns that oil prices will begin to “bite hard” into earnings if they stay above $US80 a barrel, the head of the world’s peak airline body has warned.

Speaking ahead of a gathering of the world's airline executives in Sydney next week, International Air Transport Association chief executive Alexandre de Juniac said airlines would post “solid profits” this year but high oil prices were likely to eat into their earnings next year.

“If it continues above $US80, then it will bite hard [into] the results of ... the airlines. We see more forces pushing the oil price up than down,” he told journalists in Sydney.

“Many factors are pushing the costs up, not only the fuel – fuel is a big one − but we have the cost of infrastructure, labour costs, taxes. And so we say to the community, to our members, to politicians, ‘be careful, we are probably at the peak of the cycle’.”

Mr Juniac said higher oil prices were yet to hit passengers in the form of higher fares. An increase in fares usually lagged a rise in oil prices by 10 to 12 months.