Saudi Arabia's Crown Prince Mohammed bin Salman is preparing to invest in Credit Suisse's investment bank, while other investors could include former Barclays chief executive Bob Diamond according to a report by the Wall Street Journal.

Prince Mohammed may invest around $500m in the lender's CS First Boston spinout, the newspaper said, citing people with knowledge of the matter. He has been encouraging Saudi Arabia's largest firms to expand globally, raise the country's profile as a serious investor and diversify its economy.

According to a report in the Sunday Times yesterday, Diamond, who is chief executive of Atlas Merchant Capital, is in the early stages of looking at providing capital and operational expertise to CS First Boston. 

Credit Suisse will initially hold a controlling stake in New York-based CS First Boston but it wants to bring in third party investors with the aim of exiting through a stock market listing in five years' time.