“Following on from the extended wet season in Kalimantan, approximately 417mm of rainfall has fallen at Sebuku in the last week resulting in the disruption of mining operations,” the company said in a statement.

“This rainfall event was beyond our reasonable control and its impact has affected and will affect the performance of obligations under agreements to deliver coal to customers.”

Straits said all reasonable steps are being undertaken to mitigate the impacts of the rainfall and resume normal operations.

“We will keep the market advised of developments in relation to this event, including when the force majeure condition is lifted,” Straits said.

Last week the company said it was continuing to pursue a 2007 production of 4 million tonnes, but said meeting the target would be dependent on the mine's recovery from the rainfall.