The chief executive of the manager of Norway’s now NOK10.12trn (€986bn) giant sovereign wealth fund has decided to resign from his role at the top of the organisation, but will carry on working at the fund particularly on renewable energy infrastructure, Norges Bank Investment Management (NBIM) has just announced.

NBIM, which manages the Government Pension Fund Global (GPFG), wrote in a statement: “Yngve Slyngstad has informed Norges Bank’s executive board that he will resign as CEO in Norges Bank Investment Management.

“Slyngstad will remain in his position until a new CEO takes up the position,” it said.

NBIM spokespeople were not immediately available to say why Slyngstad had decided to make the move.

In the statement, Slyngstad said: “It is an important milestone that the fund’s market value passed NOK10trn on 25 October. I am proud of having been part of building up a leading international investment organisation with talented and professional employees.”

He said the organisation had delivered good returns “for the good of our community”.

Øystein Olsen, chair of NBIM’s executive board and governor of Norges Bank, Norway’s central bank, said: “The executive board is very satisfied with the management of the fund under Yngve Slyngstad’s leadership.”

Over the 12 years, Olsen said the fund had delivered very good results and achieved a strong position internationally and in Norway.

“Yngve Slyngstad has been a distinct leader of Norges Bank Investment Management and developed a leading and global investment organisation,” he said.

NBIM said its board would now start looking for a new CEO, and once one was in place, Slyngstad will continue working at the fund, “and contribute to the further development of the investment strategy”.

“His responsibilities will include building up unlisted renewable energy infrastructure as a new investment area,” NBIM said.

In April, NBIM was given the go-ahead from Norway’s finance ministry to invest up to 2% of the fund’s value in unlisted renewable energy infrastructure.

Olsen said Slyngstad’s experience and insight would help ensure this investment area was established in a good way.

Slyngstad was appointed chief executive of NBIM on 1 January 2008, having joined the organisation in 1998 to head up and build its equity management activities. Between 1998 and 2007 he was of head of equities.