The project was deferred in December, which Santos said was due to delays in the execution of the gas sales agreement.

Under the contract, Apache and Santos will supply CITIC's Sino Iron magnetite mining project at Cape Preston with 154 billion cubic feet of gas over seven years from the second half of 2011.

Apache said its share of revenue was about $US700 million ($A971.5 million) while Santos's is about $US585 million.

The gas will be used to feed Sino Iron's 450 megawatt power station, which is currently under construction.

The contract is subject to conditions, which, if fulfilled will enable Apache and Santos, to recommence the Reindeer project.

"Development of the Reindeer field and Devil Creek plant will increase gas supplies in Western Australia, introduce a third major avenue for offshore gas to be delivered into the domestic gas market, and fuel production growth for Apache's shareholders," Apache chief executive officer Steven Farris said.

Both Farris and Santos chief executive officer David Knox said they were pleased to sign the contract with CITIC Pacific.

Reindeer is located in the offshore WA-209-P, which is operated by Apache (55%) in partnership with Santos (45%).

The field was discovered in 1997 and has a gross recoverable resource range of 410-640 petajoules (390-610 billion cubic feet) of gas.

Gas will be piped 105 kilometres to Devil Creek, about 45km southwest of Dampier, for WA's domestic gas market.

Santos said Reindeer would be capable of producing 215 terajoules of gas per day.

Clough, whose contracts for engineering, procurement and construction of the Devil Creek processing plant and installation of the offshore facilities for Reindeer were terminated in December due to the deferment, said it believes that it is ideally placed to resume work on the two projects.