Norway’s Equinor has bought an additional 5.2% stake in solar energy developer Scatec Solar, the company said late on Dec. 19, increasing its interest to 15.2% as it seeks to fulfill a pledge to invest more in renewable power.

The energy firm paid 754 million Norwegian crowns (US$84.2 million) for the stake. Scatec’s shares rose 7.3% by 11:00 GMT on Dec. 20, trading at 118.6 crowns, more than the 116 crowns paid by Equinor.

“Our shareholding in Scatec Solar remains an important long-term investment for Equinor and reinforces our strategy to develop a strong position in renewables,” said Equinor’s head of renewable energy, Paal Eitrheim.

The shares were sold by Ferd, the investment company of Norwegian billionaire Johan Andresen, which retains a 0.58% stake, Ferd said in a statement.

Equinor acquired a minority stake in Scatec Solar, Norway’s largest solar power company, in 2018, after investing in joint solar power projects in Brazil and Argentina.

Scatec had a total of 1.9-gigawatt (GW) of solar power plants in operation or under construction in its portfolio in the third-quarter, including in Egypt, Malaysia, South Africa and Ukraine, its quarterly presentation showed.

Equinor, which earns most of its money from extracting and selling oil and gas, has said it wants to invest up to 15-20% of its capital in renewable energy projects by 2030 to diversify its business.

Scatec Solar’s shares have risen 60% in 2019, lifted by higher earnings and a global boom in demand for renewable energy. Equinor’s stock is down 5.6% this year.

Equinor said it would support Scatec Solar’s further expansion.

“We are a long-term shareholder and we will support the continued long-term growth of the company,” a spokesman for the oil firm said in an email to Reuters.

Scatec Solar said in October it has increased its 2021 target for installed solar power capacity to 4.5 GW, an equivalent of more than four nuclear power reactors, from 3.5 GW previously.

Scatec Solar’s operating profit before interest, tax, depreciation and amortization almost doubled in the third-quarter from a year ago to 418 million Norwegian crowns.

($1 = 8.9522 Norwegian crowns)