DUBAI: Saudi Arabia’s central bank doubled leverage limits for retail investors looking to buy shares in oil giant Saudi Aramco, according to people familiar with the matter, part of an effort to boost local demand for what could be the world’s largest initial public offering (IPO).

Banks would be permitted to give leverage to retail customers at a ratio of 2 to 1 for every riyal they put toward buying Aramco shares, up from the normal limit of 1 to 1, the people said, asking not to be identified because the decision isn’t public.