Stephen Schwarzman, co-founder of The Blackstone Group, has sought to assuage fears over the motives of sovereign wealth funds by describing them as "model investors" which have helped stabilise the global financial system in the wake of last year's credit crunch.

Speaking at the World Economic Forum in Davos, Switzerland, Schwarzman told delegates that Blackstone has been involved with such funds for 20 years, according to a Bloomberg report.