European oil companies like BP have been stepping up investment in renewable power to diversify their businesses in the face of global moves towards a lower carbon economy to combat climate change.

Dev Sanyal, chief executive at BP’s Alternative Energy division said, renewables were attractive even though they usually offered lower returns than the company's traditional oil and gas business.

"You don't actually have the volatility of the oil and gas commodity cycle, what you've got is a stable returns structure," he said in an interview.

Lightsource BP usually seeks corporate power purchase agreements for its renewable assets, which can provide years of visibility and stability of revenue.

BP's investment will also simplify the joint venture structure as Lightsource BP seeks to accelerate its drive towards 10 gigawatts (GW) of developed assets by the end of 2023, the companies said.

Lightsource BP currently has around 2 GW of renewable capacity globally.

BP invested $200 million in Lightsource when it took a 43% stake in 2017.

No financial details relating to the stake increase on Thursday were disclosed.

By Susanna Twidale and Ron Bousso