Chavez says he plans to start a programme next year that will give away cars running on less-polluting natural gas to people who turn in old cars that consume "too much gasoline".

The socialist leader says he'll even throw in a year of free fuel – though that's a relatively minor bonus in oil-rich Venezuela, where gasoline goes for 12 cents a gallon (three cents a litre).

Saturday's offer didn't say what sort of cars would be offered or how many will be given out.

Venezuela has signed accords with companies from more than a half-dozen countries to exploit its mostly untapped natural gas reserves — the largest in South America. (AP)