Congo opens bidding for Inga 3 hydro dam investors

* Congo opens bidding for 4,320 MW Inga 3 dam investors

* BHP-Billiton expressed interest

* Inga dams could provide region with power

By Joe Bavier

KINSHASA, June 19 (Reuters) - Democratic Republic of Congo has opened bidding for partners ready to help finance the long-delayed $7 billion Inga 3 hydroelectric plant, its energy minister said on Friday.

The government has created a new company to manage the project's construction, which is expected to last eight years and has attracted interest from mining giant BHP-Billiton (BLT.L: Quote, Profile, Research).

The combined potential of Congo's Inga dams, in the relatively peaceful west of the country, has been estimated as high as 100,000 megawatts. But current output is around 700 MW and projects to revamp the dams have failed to find investment.

Congo opened the bidding process for companies interested in investing in the 4,320 MW Inga 3 plant after hosting talks on the project in Kinshasa this week, United Nations-backed Radio Okapi reported on Friday.

"Today, BHP-Billiton is interested in this production, because it wants to build an aluminium smelter in Bas-Congo (province). This is the first client we have," Energy Minister Laurent Muzangisa Mutalamu told the radio.

BHP-Billiton, the world's largest diversified miner, could contribute up to $35 million in financing, Radio Okapi reported.

Inga 3 is expected to link up with the southern African power grid to help address growing strains on the region's power supply as well as provide electricity to Congo's mining heartland in the country's southeast.

Congo's government is currently focusing on repairs and upgrades for the faltering Inga 1 and 2 hydro projects. It hopes to increase their capacity to 1,700 MW by 2012.

Congo plans one day to bring on line the 40,000 MW Grand Inga project. However, investors have so far been wary of the risk involved and have baulked at its $80 billion price tag. (Editing by David Lewis)