Rio Tinto will start exporting copper from the $6.2 billion Oyu Tolgoi Mine in Mongolia on July 9, the Mongolian government said, but it was not clear if the miner would be able to repatriate sales revenue from the mine. It had previously been reported that production would begin in June, but the start up was delayed twice.

The unlocking of ore shipments is key for Rio Tinto to secure a further $4 billion in project funding for the expansion of the mine, which will significantly boost the Anglo-Australian miner's copper portfolio and ease its dependence on iron ore, Reuters reported.

"The one great problem regarding Oyu Tolgoi's contract for the export of concentrate is no longer. First export will be on July 9th," Mongolia Mining Minister Davaajav Gankhuyag tweeted in Mongolian.

A spokesman for the mining ministry confirmed the statement.

Gankhuyag has said the delay in first exports was because the government and Rio Tinto were in disagreement on the arrangement of revenue generated from Oyu Tolgoi as well as the disclosure of the mine's $8 billion sales agreements.

Mongolia wants the sales revenues to be deposited in local banks while Rio Tinto wanted to repatriate the earnings overseas.
It remains unclear if Rio would be able to send the revenues offshore.

Rio subsidiary Turquoise Hill Resources Ltd owns a 66 percent stake in the mine, with the Mongolian government owning the remainder.

Rio Tinto's Australian shares were down 2.1 percent on Monday afternoon. The broad Australian stock market was down 0.5 percent.