* Contractors at ArcelorMittal Liberia iron ore ops declare force majeure
* Aureus Mining, Tawana Resources send non-essential staff home
* WHO says Ebola an international health emergency (Adds evacuation of ArcelorMittal contractors from Liberia)
By Karen Rebelo
Aug 8 (Reuters) - Contractors at ArcelorMittal SA's iron ore mine in Liberia are evacuating the country and other miners are sending staff home to prevent the spread of the deadly Ebola virus.
Mining companies in West Africa are acting swiftly to keep Ebola at bay, screening employees and restricting access to remote mining camps while keeping production of iron ore and gold ticking.
A prolonged outbreak, however, will threaten mineral production in Sierra Leone, Liberia and Guinea if essential supplies are disrupted and employees stay away from work too long.
Or worse: should a miner or family member contract the virus.
"I think everyone is mindful that it's something that has the potential to impact businesses," said Mark Bristow, chief executive of Randgold Resources Ltd, which mines gold in Mali, across the border from Guinea.
Though it has no mines in countries affected thus far, Randgold is among several miners in West Africa to have launched preventive measures against an outbreak that has killed more than 900 people in four countries.
The World Health Organisation has called the epidemic an "extraordinary event" that constitutes an international health risk. There is no known cure for Ebola, which is transmitted through direct contact with bodily fluids.
The outbreak began in eastern Guinea in February, before spreading to Sierra Leone and Liberia. Cases have also been recorded in Nigeria.
Not a single case of Ebola has been recorded among the employees of those companies mining and exploring large reserves of oil, iron ore, bauxite and gold in the region. But some have sent workers home and scaled back or suspended exploration.
ArcelorMittal, the world's largest steelmaker, said contractors working on the expansion of its iron ore operations in Liberia had declared force majeure and were evacuating the country.
ArcelorMittal currently mines and ships 5 million tonnes of iron ore annually in Liberia and it plans to triple shipments from the country.
Australia-listed Tawana Resources NL, which is developing the Mofe Creek iron ore project 20 km (12 miles) from the Liberian coast, said on Friday it was halting non-essential field work. Its stock fell nearly 19 percent.
Toronto-based Aureus Mining Inc granted leave to non-essential staff at its New Liberty gold deposit in Liberia.
"What we have seen now, because of the movements of non-essential personnel, is that exploration activity is starting to be curtailed," said Paul Renken, analyst at VSA Capital, an investment bank focused on natural resources.
Canadian Overseas Petroleum Ltd, ExxonMobil Corp's partner in a venture to explore the Block LB-13 project off the coast of Liberia, has said that drilling will be delayed due to the "reduced presence of expatriates".
Some miners, including Sierra Rutile Ltd and African Minerals Ltd, are screening staff for early signs of the virus and running community education programmes.
AngloGold Ashanti Ltd is also controlling the movement of workers to and from its Siguiri gold mine in Guinea, only 25 km from the town of the same name, where cases have been reported, said company spokesman Chris Nthite.
But it will be difficult, if not impossible, for mining companies throughout West Africa to restrict the movement of their employees indefinitely.
"If the situation goes on for another two or three months, then I think we should start to expect problems," said John Meyer, a mining analyst at brokerage SP Angel.
He said this would be particularly true in the event that Ebola were to afflict communities that serve the mines, "because the mines will want to cut themselves off, but the families will want to be with their breadwinners". (Additional reporting by Abhiram Nandakumar in Bangalore; Writing by Robin Paxton; Editing by Savio D'Souza and Kirti Pandey)