Born in 1940 and a citizen of the Mediterranean island of Malta, Zammit Cutajar led the UN Climate Secretariat in Bonn from 1991-2002 and has had other posts in the UN system.

Zammit Cutajar will lead work on how to confront rising temperatures widely blamed by scientists on fossil fuel emissions that could spur more heatwaves, floods and droughts and drive up sea levels by almost a metre by 2100.

Environmentalists and climate activists welcomed the appointment.

"They made a good decision," said Alden Meyer of the Union of Concerned Scientists. "He's the right man to do the job with the needed experience."

"We have a great chair who will help to bring the parties together in a really constructive way," Richard Kinley, the officer-in-charge of the Climate Secretariat, told Reuters.

Kyoto obliges almost 40 industrialised nations to cut emissions of heat-trapping gases by at least 5 percent below 1990 levels by 2008-12. The United States pulled out in 2001, branding Kyoto an economic straitjacket and saying it wrongly left out developing nations.

CARBON MARKETS

Environment ministers agreed in Montreal last year to start discussing an extension of Kyoto in Bonn, partly to reassure investors in volatile markets for trading industrial emissions of carbon dioxide that the system would last beyond 2012. The conference also chose Luiz Alberto Figueiredo Machado, a top official in Brazil's Foreign Ministry, as vice-chairman after developing nations objected to Zammit Cutajar, from a European Union nation, having sole leadership.

The Bonn meeting, lasting until the end of next week, will start examining how to extend cuts. The EU, for instance has said that far deeper cuts will be needed, but Canada has said that even its targets for 2012 are "unachievable".