LONDON (Reuters) - Tethyan Copper, a joint venture of London-listed copper miner Antofagasta Plc and Canadas Barrick Gold Corp, has filed a 'notice of dispute with Balochistan province over its Reko Diq mine. Tethyan said it filed the notice with the provincial regulator after the region refused to meet its executives or extend a deadline for it to respond to objections that officials had raised over a mining lease being sought for the Reko Diq copper-gold project. Reko Diq only the second significant project in the mineral-rich region and potentially a source of much needed inward investment holds an estimated 5.9 billion tonnes of mineral resources, with an average copper grade of 0.41 percent and an average gold grade of 0.22 grams a tonne. It is my feeling that there is a degree of confusion, Tethyan Chief Executive Tim Livesey told Reuters. I am very hopeful we will meet ... and I hope we can resolve (the dispute). The two sides now have 120 days to meet and reach an agreement. Failing that, Tethyan said it would move to seek a resolution through international arbitration. International courts cannot force the attribution of the license by the local government, but Tethyan could seek compensation for cash invested and loss of future earnings. The joint venture partners spent $200 million in 2006 buying the exploration license from rival BHP Billiton. Construction has been projected to cost some $3.3 billion, but that is expected to climb given rising costs faced by the mining industry, particularly in remote locations like Balochistan. Tethyan filed an application for a mining lease in February and had hoped for a decision last month. Instead, officials in Balochistan, where there has been growing anger about outsiders exploiting natural resources, raised 10 objections. The points varied from raising concerns over the validity of our company registration to raising concerns over the quality of the exploration and feasibility study, Livesey said. It was immediately clear to us that we could not understand their position on some of these issues, he said, adding that some of the objections were in contravention of existing agreements. Livesey said Tethyan sought to meet the local government and a 60-day extension to the period it had to provide a response to the objections, but was refused. Tethyan filed its responses to the objections on Thursday, the deadline, but Livesey said the responses were interim as the two sides had not yet met. Reko Diq, if it went ahead successfully, would mark the largest foreign direct investment into Pakistan mining and a major investment in Balochistan, At its peak, it would likely employ 11,000 people. The project, which would produce 200,000 tonnes of copper and some 250,000 ounces of gold a year, had been expected to begin production in 2015, but that was pushed back due to delays over the mining lease even before Thursdays notice of dispute.