HARARE, June 13 (Reuters) - Zimbabwe's government will soon lift its ban on diamond exports and expects to trade more than 4 million carats from the controversial Marange fields, state media reported on Sunday 13 June.

Mines minister Obert Mpofu, last month stopped all diamond exports, including from Rio Tinto's (RIO.AX) (RIO.L) Murowa mines and the privately owned River Ranch, until stones from the government's Marange fields were certified by industry regulators.

Last week, a monitor appointed by the Kimberley Process Certification Scheme (KPCS) to assess the government's mining operations at Marange said Zimbabwe had met the minimum conditions set by the industry regulator and could start gem exports.

The state-controlled Sunday Mail newspaper quoted Mpofu saying Zimbabwe would now lift the diamond export ban and begin the auction of its own gem stockpile of 4 million carats, which the paper said could be worth up to $1.7 billion.

"We have met the criteria and what is now left is to start exporting the diamonds," Mpofu is quoted saying.

"The report is good and we have to go by its findings."

The government has partnered South African companies, Grandwell Holdings and Core Mining, to mine the Marange diamonds in two 50-50 joint ventures.

Rights groups are pushing for a trade ban on the Marange stones, alleging serious abuses by security forces deployed by the government to stop illegal diamond digging after up to 30,000 panners descended on the poorly secured fields in 2006.

Zimbabwe came under international spotlight following reports of widespread atrocities in Marange, and the government agreed to a process of assessment by the KPCS.

In a report released last week but due to be presented to the Kimberley Process working group on monitoring on Monday 14 June, South African monitor Abbey Chikane expressed concern over the continued presence of the army in Marange, but warns against their rapid removal, saying this could trigger illegal digging. (Reporting by Nelson Banya, Editing by Louise Heavens)