A 10-year deal has been signed by Swiss-based energy traders Mercuria to advertise uncommitted coal from South African miner Optimum Coal Holdings' Optimum and Koornfontein mines. It is the fourth-largest coal exporter in South Africa.

Initially, about 1.3 million tons of coal a year will be brought from the Koorfontein mine.

In order to increase sale of uncommitted coal, Optimum Coal Holdings has planned to expand its mine, by increasing adjoining reserves. The free coal is in abundance there.

The thermal coal, which is currently being produced at the 6 million ton Optimum mine, will be marketed by BHP Billiton until 2021.

The sources said that Mercuria may target the Asian market with this coal, as the chances of growth are brighter there. Mercuria had paid a sum of around $100 million for getting the marketing rights. It would be logically more correct to focus on Asian market.

South Africa exported around 60 million tons of thermal coal in 2009 which may rise to the extent of 65 million in 2010, out of which 30% is expected to be sold in Asia.