CAPE TOWN (Reuters) - Spot uranium prices are likely to remain choppy in the face of "anaemic" production and will remain so for the near term, the head of a consulting firm that publishes uranium prices said on Monday.

Kazakhstan has so far been the strongest producer of the silvery white metal used as the basic fuel for nuclear power, but current world production is estimated to last about 3 to 5 years, leaving a potentially big gap in the market.

"A big question about production expansion still remains," Jeff Combs, president of Ux Consulting Co. told a mining conference in Cape Town.

"The production so far has been pretty anaemic, with the exception of Kazakhstan, and the spot price will remain volatile until a clear picture of future output emerges."

He said although the long term contract price was steady, it could go up if projected output expansions fail to materialise.

Kazakhstan and Africa combined represent the big growth areas in a race to meet fast-growing world demand in the midst of a global nuclear renaissance.

"Without Kazakhstan, we would be seeing much higher prices than we have now," Combs said.

Uranium prices have nearly quadrupled in the last two years as stockpiles vanish.

Investors are betting on a flurry of new nuclear power plants, especially in China and Russia. The United States, Britain and India are also ramping up plans for new reactors.

Kazakhstan's uranium production rose more than a quarter last year to 6,637 tonnes, from 2006, and has plans to boost output that would make it become the world's biggest producer.

In Africa, Namibia plans to open four new uranium mines by 2010 that will boost its output to 10 percent of world production.

It follows a boom in uranium exploration last seen during the energy crisis of the 1970s.

Namibia is one of only three African producers of uranium - the others are Niger and South Africa. The three countries made Africa the world's top producer of uranium in 1980, after exploration flourished on the continent due to robust prices.