Mexico said that it would slash its carbon pollution by 50% before 2050, joining Brazil among large developing economies to pledge large reductions in greenhouse gases.

Mexico will reach this goal through voluntary and non-binding commitments to improve energy efficiency in heavy industry, notably in the cement and oil sectors, Environment Minister Juan Rafael Elvira told a press conference.

He unveiled key elements of the plan at the UN Framework Conference on Climate Change in Poznan, Poland, where 192 nations are striving to forge a global climate pact before 2010.

More details would be unveiled in February by Mexican President Felipe Calderon, Elvira said.

The target, he said, was to reach a level of half the 650 million tonnes of greenhouse gases that was emitted in 2002, the year Mexico will use as a baseline to measure change.

The oil and cement sectors both had "a great potential for reduction", but Mexico will need help in attaining its goals, said the junior environment minister, Fernando Tudela, also in Poznan.

"We need to have secure financing, we can’t rely only on funds coming from the Clean Development Mechanism (CDM)," he said.