Knut Kjaer, founder and chief manager of Norway’s $328bn sovereign wealth fund for the past decade, has resigned to pursue new challenges.

Mr Kjaer led the planning for the founding of the fund, which receives a proportion of the Norwegian government’s huge annual oil and gas revenues. He then took over in January 1998 as chief executive of Norges Bank Investment Management (NBIM), an arm of the central bank that manages the oil fund as well as most of the bank’s foreign exchange reserves.