Rio Tinto Group, Vale SA and Cameco Corp. are among companies that expressed interest in setting up joint ventures in Kazakhstan, according to an official at the mining unit of the country’s sovereign wealth fund.

“Every company seeks a unique mine and our task is to find one to bring global miners to Kazakhstan,” Nurlan Zhakupov, a managing director at the Tau-Ken Samruk mining unit, said in an interview by phone from Almaty yesterday. “Rio Tinto, Vale and Cameco” are interested in the company’s proposals, he said.

Zhakupov was speaking after a presentation at the Central Asia Mining conference in Almaty. Cameco Chief Executive Officer Jerry Grandey and Rio Tinto’s head of exploration, Eric Finlayson, attended the conference.

“Kazakhstan is one of the largest countries in Central Asia with multimineral potential,” Vale said in an e-mailed response to questions today. “Vale has begun a program to evaluate opportunities for copper, nickel, phosphate, potash and uranium,” it said, without elaborating.

“We’ve been exploring in Kazakhstan for 10 years,” Rio spokesman Nick Cobban said by phone in London. “It’s an area of interest for us but we haven’t reached any agreement.” Cameco spokesman Lyle Krahn didn’t pick up calls to his office phone in Saskatoon, Canada, outside of regular business hours.

Under the plans, the state-run company may retain at least a 25 percent stake in any joint ventures, while providing help on developing mines, Zhakupov said. Tau-Ken Samruk, created to manage government holdings in metals companies, said June 22 it would buy stakes in local mine operators to help them weather the nation’s worst economic crisis in more than a decade.