By Sarah Shearman

LONDON, July 4 (Thomson Reuters Foundation) — Britain's National Trust will sell all of its investments in the fossil fuel industry by 2022, the conservation charity announced on Thursday.

The charity invests £45 million ($56.61 million) in fossil fuel companies — 4% of its £1 billion stock market portfolio — despite having itself warned of the dangers of climate change.

But it will aim to offload the majority of investments in oil and gas companies, which include Shell, BP, and Total, within 12 months, chief financial officer Peter Vermeulen told the Thomson Reuters Foundation by phone.

It will instead favour green startups and other companies that deliver positive environmental outcomes.

The National Trust's stock market fund is an important source of revenue for the charity, which looks after coastlines, land, and historic properties across Britain.

Vermeulen said not enough progress had been made by oil and gas companies to transition to a low carbon economy since the 2015 Paris climate agreement.

"Oil and gas companies have been insufficient in actually changing their business models to a low carbon economy," he said. "So as a conservation charity we have called time on that and said we are not going to invest in those companies any more."

The move comes after British charities and faith groups asked the government in March for legal guidance on investing in companies that contribute to climate change.

Both the National Trust and the Church of England were named in the open letter to the government.

Shareholder activism, where financial backers and board members push the companies they invest in to make ethical changes, is growing in prominence.

BP, for example, faced pressure from shareholder groups to set tougher targets to combat climate change at its annual meeting in May.

Shareholder action, however, has yet to lead oil and gas companies to "materially change their behaviour and invest vastly more than 10% of their capital investment into low carbon technologies," Vermeulen said.

"This was part of...making sure that in all of our actions as a conservation charity we are looking after and caring for nature, beauty, and history," he said.

The charity currently invests £4.7 million in companies that advance wind technology, energy storage, and water efficiency, about 10% of its investments in the oil and gas industry.

($1 = 0.7950 pounds) (Reporting by Sarah Shearman @Shearmans, Editing by Tom Finn. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's and LGBT+ rights, human trafficking and slavery, property rights, social innovation, resilience and climate change. Visit http://news.trust.org to see more stories)