China Railway Group Ltd (SHA 601390; HK 0390) said it has signed a supplemental agreement with China Metallurgical Group allowing the latter to become one of its partners in establishing a mining joint venture in Congo.

In April, the company announced a tieup with China Hydraulic and Hydroelectric Construction Group Corp (Sinohydro) and the government of Congo to form a 100 mln usd mining joint venture in Congo.

Under the new agreement, two wholly-owned subsidiaries of China Railway will pay a total of 28 mln usd to hold a combined 28 pct stake in the venture, down from the original 43 pct, while two wholly-owned units of Sinohydro will cut their combined stake to 20 pct from 25 pct.

Meanwhile, the new partner China Metallurgical Group will pay 20 mln usd to take a 20 pct stake in the venture, China Railway said in a statement filed with the Shanghai Stock Exchange.

On the Congo side, state-owned La Sino-Congolaise Des Mines will still hold a 20 pct stake, but property firm La Societe Immobiliere Du Congo will take the place of Gilbert Kalamba Banika, an individual investor, for 12 pct of the venture.

Total investment to develop the Congo mines is projected at 2.9 bln usd, China Railway said earlier.

Based on a preliminary feasibility report, proven copper reserves at the prospective mines are about 6.8 mln tons, and proven reserves of cobalt are about 420,000 tons.