CHINA has asked government officials to stop using four-wheel drive cars and other gas-guzzlers to lower emissions and protect the environment, state media reported yesterday.

Beijing has pledged to cut emissions and energy consumption amid growing domestic and international concern that China's rapid industrialisation has placed an unbearable strain on the environment.

"Government-issued cars should set an example," the official People's Daily newspaper quoted a notice from State Council administrative organs as saying.

Officials are encouraged to take public transport on official business, and leave cars at home during national holidays. The notice carried a reminder that renting out government cars for profit was illegal.

It also froze new car orders from the departments, to lower the number of vehicles on the government payroll and clear out a backlog of cars in violation of regulations.

Officials are instructed to organise training and "fuel conservation competitions" to lower fuel consumption by 20 per cent in 2008.

China also set up its first exchange for trading emissions credits covering more than a dozen chemicals, Hong Kong newspaper the South China Morning Post reported yesterday.

The idea behind emission credits trading is that the market creates a choice: either spend the money to cover the costs of cutting emissions, or else pay someone else to cut their pollution, the BBC explained.