MONROVIA (Reuters) - Liberia has opened a second licensing round for offshore oil acreage, with three international companies bidding for a total of five blocks, Minister for Land, Mines and Energy Eugene Shannon said.

The three companies taking part were Anadarko Petroleum Corp, Luxembourg's Mittal Investments S.a.r.l., part of a group that includes top world steel firm Arcelor Mittal, and Hong Kong Tongtai Petroleum.

Liberia, Africa's oldest independent republic, was torn apart by a 14-year civil war which ended in 2003 after killing some 200,000 people.

The West African state is now looking to rebuild its war-ravaged economy and infrastructure by giving opportunities to foreign investors to develop its natural resources, which also include rubber, timber and iron ore.

"The hope to get oil in Liberia is high because of Liberia's position. It is located in the Gulf of Guinea," Shannon said at the ceremony launching the licensing round late on Thursday. He estimated the probability of a discovery at 50-70 percent.

Liberia lies on the north-western edge of the oil-producing Gulf of Guinea, west from minor oil producer Ivory Coast and from Ghana, where foreign companies including Anadarko have made recent major discoveries.