Société des Mines de Loulo (SOMILO) S.A. is an 80% owned subsidiary of Randgold Resources Limited and holds the 372km² Loulo mining lease in western Mali. The remaining 20% is held by the Government of Mali. The project has been developed as both an open pit and underground operation by Randgold Resources to exploit two main orebodies; Gara and Yalea, as well as a number of satellite deposits. The original Gara orebody was discovered by Syndicate d’Or in 1981 and the Yalea orebody, the principal orebody, by Randgold Resources in 1996/1997. The mining lease boasts a significant portfolio of prospective targets which are being explored and evaluated through an ongoing exploration programme. SOMILO is managed by Randgold Resources Limited, an African focused gold mining and exploration company incorporated in the Channel Islands and listed on the London Stock Exchange (UK) and Nasdaq (USA).

The Loulo mine currently consists of two main open pits, Yalea and Gara, smaller satellite pits and the new Yalea underground mine. A second underground mine, Gara, is at its final planning stage.

Total resources at Loulo, including satellite deposits, currently stand at 11.41 million ounces of gold of which 9.18 million are in the measured and indicated categories. Open pit reserves, based on a gold price of US$650 per ounce and stockpiles, currently total 0.88 million ounces and underground reserves, 6.32 million ounces.

The plant has been upgraded and is now able to process an average of 3.2 million tonnes per year. In 2008, 26.23 tonnes of material were mined and 258 095 ounces of gold produced. The mine production is planned to ramp up to 400 000 ounces by 2011 once the underground mines are fully operational.