Villepin said France would also back moves to curb greenhouse gas emissions beyond 2008-2012, the first period covered by the international Kyoto Protocol on climate change.

"We will continue our efforts to convince all industrialized countries and the large emerging countries to join us," Villepin said.

His comments came as officials from 150 countries prepare to meet in Montreal, Canada on November 28 for a UN climate change summit to help shape the Kyoto Protocol post 2012.

The United States and Australia have declined to ratify the pact, and developing nations, such as China and India, are exempt from emissions caps that all four countries say threaten economic growth.

France aims to boost the use of renewable energy, such as solar and wind power, to 21 percent of electricity output by 2010 from 15 percent now as part of its bid to curb emissions.

"Beyond this protocol, we wish to enter new engagements on CO2 emissions," Villepin said. The government said it planned to boost solar power producers by paying them substantially more for the electricity they produce.

Tariffs for supplies to homeowners would rise 50 percent next year, with prices for supply to businesses rising 100 percent, the government said.

At the same time tax credits for buying solar-fired heaters would be raised by 10 percentage points to 50 percent in 2006.