KINSHASA, May 24 (Reuters) - The Chinese company buying Freeport McMoRan Inc's majority stake in the Tenke copper mine has told the Congolese government that Freeport staff will oversee the operation for a transitional period of 12 to 18 months, an adviser to the prime minister said on Tuesday.
A delegation from China Molybdenum Co (CMOC) is visiting Democratic Republic of Congo this week to reassure government officials who have expressed alarm about the change of ownership of the largest private investment in the country's history, the adviser said.
CMOC agreed on May 9 to buy Freeport's 56 percent stake in Tenke, one of the world's largest copper mines, for $2.65 billion in cash.
Government officials have complained that they were not informed in advance of the deal.
The delegation, which includes CMOC chairman Chaochun Li and the CEO of its overseas operations, Kalidas Madhavpeddi, also told Prime Minister Augustin Matata Ponyo on Monday that the mine would honour its tax and environmental commitments, the adviser said.
"There won't be a major change for at least 12 to 18 months," the adviser told Reuters. "That's what (the delegation) came to do -- reassure the Congolese authorities and the personnel who work (at Tenke) that nothing is going to change in the short term."
CMOC did not immediately respond to a request for comment but the handover period was confirmed by a Freeport spokesman.
"We will continue to provide support and will operate (Tenke) for a period of time; up to one year after the transaction closes," he said.
The deal is expected to close in the fourth quarter of this year, he added.
Congo's mines minister said this month that he suspects Freeport is hiding the true value of the sale and should pay tax on the deal.
The prime minister's adviser added that the government is continuing to look into the circumstances of the sale.
Congolese state miner Gecamines controls a 20 percent stake in Tenke and Toronto-based Lundin Mining holds the remaining 24 percent.
Reporting By Aaron Ross; Editing by Edward McAllister and David Goodman