SYDNEY - BHP Billiton, the world's largest miner, has declared force majeure on some copper and uranium contracts after damage to a shaft at its Australian Olympic Dam mine, it said on Wednesday. The miner has sent force majeure notices to some customers, a move that frees it from liability if it can't meet a contract due to events beyond its control.

It also said in a statement that the shaft at Olympic Dam would be out of operation for at least a month.

Olympic Dam produced 194,000 tonnes of copper and 4,000 tonnes of uranium in the year ended June 30, 2009. (Reporting by James Regan and Jonathan Standing, editing by Mark Bendeich