AAP

Leighton Holdings Ltd's Asian business has secured an $195 million expansion on a Mongolian coal mine contract.

Leighton said on Wednesday that Energy Resources had requested Leighton Asia expand production capacity at the UHG coal mine in Mongolia's South Gobi region.

Leighton Asia won the mining contract for the UHG mine in February this year, and coal production began in March.

The contract has been expanded from production of 2.5 million tonnes of coal per year to five million tonnes per year by December 2010, taking the value of the contract to $480 million.

"This request to expand capacity at UHG mine is testament to the strong working relationship we have with Energy Resources," Leighton Asia managing director Hamish Tyrwhitt said in a statement.