The move is the first step by the world's airlines, which account for around two percent of global pollution, to steer the debate on an emissions pact towards a deal they are happy with, rather than having one imposed on them.

Air France/KLM, British Airways, Cathay Pacific, Virgin Atlantic and airport operator BAA issued the call in Hong Kong and outlined a series of principles a new global deal for aviation must adhere to.

Conservation groups such as WWF say aviation has not been doing enough to tackle the sector's growing share of greenhouse gas pollution and must pay for its emissions like many other industries.

Emissions from international aviation comprise about two percent of mankind's total carbon dioxide (CO2) pollution from burning fossil fuels and deforestation and are expected to keep rising as economies and populations grow.

Green groups and governments say airlines should be part of emissions trading schemes as a start. "This is the first time a group of airlines has got together to call for aviation to be included in a climate change treaty," Dominic Purvis of Cathay Pacific said.

"We're contributing to climate change and we need to play our part," said Purvis, the airline's general manager for environmental affairs. Nations meet at the end of the year in the Danish capital Copenhagen to try to agree on a broader climate pact that replaces the Kyoto Protocol, the United Nations' main weapon to fight global warming

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Kyoto's first phase ends in 2012. The idea is to find a way for developing nations to sign up to emissions curbs and to include aviation and shipping, which together make up 5 percent of mankind's CO2 emissions, a fifth of which come from US emissions of 6 billion tonnes a year.

The United Nations' International Civil Aviation Organisation (ICAO) has been working for more than a decade to develop a global scheme to tackle aviation emissions. Purvis said the four airlines would discuss existing proposals to curb emissions and feed the group's ideas to ICAO and other airlines to try to settle on a fair and environmentally sound approach for inclusion at Copenhagen.

"The best thing is to have something effective and easy to apply and cost-effective rather than to wait for someone else to come up with it and potentially take a course of action not necessarily appropriate for aviation," he said.

The four airlines and BAA are meeting in Hong Kong and in their communique laid out principles for a global approach that included balancing social and economic benefits of flying with the industry's responsibility to cut global emissions.

The airlines also said a new global climate deal for aviation must preserve competitiveness and avoid market distortions. Many airlines say only a global approach is fair and criticize the European Union's decision to include aviation in the bloc's emissions trading scheme from 2012. Airlines will have to pay for their emissions over the entire route, not just within EU airspace, a rule many Asian airlines flying long-haul routes to Europe say is unfair.