Saudi Aramco is considering the sale of a stake in its sulphur business, three sources with knowledge of the matter told Reuters, extending a strategy of tapping its infrastructure assets to raise tens of billions of dollars. Aramco, the crown jewel of the world's largest crude exporter, has been seeking outside capital to fund the kingdom's ambitious diversification agenda amid mounting fiscal pressure. The oil giant has been actively seeking to sell assets, improve efficiency and cut costs, Reuters reported exclusively last year. The total value of assets from its vast infrastructure empire that it may tap for fundraising could reach around $50 billion, according to one of the sources and Reuters calculations. Aramco invited banks to pitch last month for the sulphur deal, known internally as Project Yellowstone, the sources said, and could raise up to $7 billion, one of them added. Aramco, the world's biggest energy firm, declined to comment.