(Bloomberg) -- Norway’s sovereign wealth fund has sold its entire portfolio of companies focused on oil exploration and production, marking a major step away from fossil fuels for the investing giant.

The portfolio, worth about $6 billion in 2019, was fully exited by the end of last year, Trond Grande, the fund’s deputy chief executive, said by phone on Thursday. The move completes a years-long process to reduce the giant investor’s exposure to a sector that has defined Norway’s economy for the better part of half a century.

Grande spoke after the fund revealed a roughly $10 billion loss on oil and gas holdings in 2020 that had been valued at over $40 billion at the start of the year. Overall, 2020 was one of the fund’s best years ever, with the total portfolio generating $123 billion in returns, buoyed in particular by its holdings of tech stocks.

Norway’s wealth fund, the world’s biggest, started turning its back on oil and gas more than three years ago. The intention back then was to diversify away from an industry to which Norway’s economy was heavily exposed, with a view to addressing a key financial risk. But the fund’s new CEO, Nicolai Tangen, has also made sustainable investing an explicit focus of his strategy, and says all portfolio managers who work for the fund need to operate with that in mind.

Tangen has assigned about 10 asset managers to hunt down investment opportunities in renewable infrastructure. The fund, which the CEO says has yet to invest a single cent in the area, wants the portfolio to eventually reach about 1% of the total $1.3 trillion fund. Tangen has already admitted that might prove hard, with demand for renewable infrastructure assets driving up prices.

“We’re working relentlessly to get something under our belts here, and we hope that will happen this year,” he said in an interview. “We’re looking for wind and sun projects in Europe and America.”

Back in October, Tangen said “there’s a lot of competition” for the kind of projects the fund would be interested in buying.

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