Angolan state-owned diamond company Endiama said on Wednesday the southwestern African nation had 100 mines open for exploration by private investors.

Endiama wants to become one of the biggest diamond producers in the world, Endiama, the world's fifth-biggest diamond producer, said in the statement.

Companies interested in exploring for diamonds in Angola have to partner with Endiama, according to Angolan law. The 100 mines open for exploration are spread across 14 of the 18 provinces in Angola -- a country twice the size of Texas.

Diamond production in Angola has been growing rapidly since a 27-year civil war ended in 2002. Yet only 42 percent of Angola's diamond reserves, which some analysts estimate at over 200 million carats, are being explored.

The end of the war paved the way for diamond companies like De Beers, BHP Billiton and Anglo American to partner with Endiama and take advantage of the countries untapped diamond reserves.

There are currently 61 mining concessions in Angola but only 14 are producing diamonds, Endiama said.

Endiama plans to increase diamond production by about 10 percent to 10.5 million carats in 2009, compared with the previous year.

Also on Wednesday, workers at an Endiama subsidiary began a strike over wages.

Some 130 workers at Enditrade, which provides logistical support and transportation for Endiama's diamond mines, were in talks with company officials on Wednesday.

Enditrade and its workers are trying to reach an agreement, Sebastiao Panzo told Reuters, adding an undetermined number of workers who had joined the strike would not affect Endiama's overall diamond production.

Prices of commodities have plunged in recent months as the United States, Europe and Japan grapples with the economic slowdown. The United States accounts for about half of world diamond demand.

2009 will be a difficult year, Endiama Chairman Manuel Calado said recently, adding that demand for diamonds was also falling because banks were cutting back on loans to traders who purchase gems from countries like Angola. (Reporting by Henrique Almeida; editing by Sue Thomas)

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