The Norwegian Government Pension Fund Global (GPFG) has bought a 25% stake in Regent Street’s Quadrant 3 building in London’s West End from the Crown Estate.

Norges Bank Investment Management (NBIM), which manages the NOK4.9trn (€591bn) sovereign wealth fund, said it paid £97.5m (€117.9m) for the stake, valuing the entire building at £390m.

The Crown Estate, which manages properties technically belonging to the Queen, said it was keeping a 75% interest in the property and would continue to manage the asset on behalf of the partnership.

NBIM said the deal expanded the Regent Street partnership, which the GPFG and the Crown Estate had started in 2011.

The government pension fund already has a 25% stake in the rest of Regent Street.

Paul Clark, director of investment at the Crown Estate, said: “We are delighted to extend our relationship with NBIM, further developing our strategic partnership model, which is central to the future of our business.”

This deal had increased the amount of third-party capital the Crown Estate managed for institutional investors to more than £800m, he said.

Quadrant 3 contains 270,000sqf (25,000sqm) of office, retail and restaurant space over basement, ground and seven upper floors, the Norwegian asset manager said.

The building was recently developed by the Crown Estate and completed to a BREEAM Excellent environmental standard, it said.

The Crown Estate said the Regent Street partnership between it and NBIM – now valued at £2.8bn – was transforming the street via the partners’ £1bn investment programme.