The stakes were small compared to Storebrand's $91 billion in assets under management but their sale marks an escalation from the company's historical preference to engage with companies over such issues.

The move comes amid growing concern about trade groups lobbying to soften green finance rules in Europe.

"If you have corporates that are spending a lot of resources and energy to try to avoid that regulation that is required, that is clearly not supportive and not in the long-term interest of anybody, if you want to reach the climate goals or the (United Nations') sustainable development goals," Storebrand Asset Management CEO Jan Erik Saugestad told Reuters.

Governments across the world are tightening rules on carbon dioxide emissions as they aim to meet the terms of the Paris Agreement on climate.

Storebrand said it had sold its $12.3 million stake in ExxonMobil, a $10.4 million stake in Chevron, a $3.8 million stake in miner Rio Tinto and its $2.7 million holding in chemicals company BASF.

Chevron said its board of directors was considering a recent shareholder proposal calling for increased disclosure on climate change-related lobbying and was working to take appropriate action to address shareholders' concerns about this "important issue".

"Chevron engages with numerous third-party organizations that take positions on a range of issues, including climate change," a company spokesman told Reuters.

"We are not always aligned with all the views of those organisations, but it's important for us to be part of conversations on challenging issues where there are multiple points of view."

ExxonMobil said "society faces a dual challenge of increasing supplies of energy to meet the demand of a growing world population while also addressing the risks of climate change.

"Our company plays an important role in addressing both aspects of that challenge," the company said in a statement.

Rio Tinto declined to comment on Storebrand's decision. It says on its website that each industry association it joins is different and include a range of different views which may differ from Rio Tinto's views.

"We believe that diverse and differing views should be heard and are an important step in finding compromise that allows progress to be made," it said.

BASF was not immediately available for comment.

(Editing by Jason Neely)

By Gwladys Fouche and Simon Jessop