The combined wealth of 12 billionaires of Arab origins has increased by 9 percent, to $168.6 billion, in less than three months, Forbes Middle East reported on Friday. The increase is mainly due to an expansion of Mexican billionaire with Lebanese Origins Carlos Slim Helu’s wealth, who gained $12.7 billion in almost 12 weeks, bringing his net worth to a total of $93.9 billion by the end of May. Helu – the honorary chairman of Latin America’s biggest mobile telecom firm América Móvil – is the world’s richest person of Arab descent, as he climbed three positions in the real-time billionaire rank…