GENEVA — A Swiss court on Friday convicted the French-Israeli mining magnate Beny Steinmetz on charges of corrupting foreign public officials and forging documents, in a trial over his successful bid to reap lavish iron ore resources in the West African nation of Guinea.
Mr. Steinmetz, one of the richest people in Israel, was sentenced to five years in prison and ordered to pay a $56.5 million fine.
The case centered on alleged payouts of millions of dollars to a former wife of an ex-president of Guinea, Lansana Conté, who died in 2008. The trial exposed the shady and complex world of deal-making and cutthroat competition in the lucrative mining business.
His defense lawyer, Marc Bonnant, said he would “immediately” appeal the ruling. Mr. Bonnant said his client had not given “a single dollar” to any official of the Guinea regime during Mr. Conté’s presidency.
The prosecutor, Yves Bertossa, told reporters he was “satisfied” with the verdict, and the Swiss transparency group Public Eye hailed a “landmark ruling.”
“This conviction of a high-profile business figure not only sends a strong signal to the commodities sector as a whole, but also demonstrates the vital need for Switzerland to finally remedy the legal loopholes that allow such predatory practices,” it said.
Mr. Steinmetz, 64, denied the charges, which date to the mid-2000s and involved his company, BSG Resources, squeezing out a rival for mining rights to vast iron ore deposits in the Simandou region of Guinea.
The Geneva prosecutor’s office alleged that Mr. Steinmetz and two other defendants engaged in corruption of foreign officials and falsification of documents to hide from authorities and banks the paying of bribes. Some of the funds allegedly transited through Switzerland — and the case has been investigated in Europe, Africa and the United States.
The Swiss prosecutor’s office said Mr. Steinmetz, starting in 2005, crafted a pact of corruption with Mr. Conté, who ruled the West African country from 1984 until his death, and his fourth wife, Mamadie Touré, involving the payment of nearly $10 million.
In its court filing, the prosecutor’s office said BSG Resources won exploration and exploitation licenses in Guinea between 2006 and 2010 in the Simandou region, and that its competitor — the Anglo-Australian mining group Rio Tinto — was deprived of the concessions it had held until then in that region.
In 2014, the Guinean government, after a review launched by the democratically elected president, Alpha Condé, accused Mr. Steinmetz’s company of corruption, paying millions of dollars through a representative to Ms. Touré.
Civil society organizations have lobbied for proposals that would add accountability for businesses headquartered in Switzerland for their actions abroad. One such proposal, which would have held companies based in Switzerland liable for human rights violations and environmental damage committed by subsidiaries abroad, failed in a referendum last year.