BHP has started talks with Australia’s Woodside about merging its petroleum division, which would be the world’s largest mining company’s exit from the oil and gas market. BHP, which is listed in both London and Sydney, said on Monday that a merger with Woodside was one of several options under consideration as part of a strategic assessment of its petroleum sector. It further stated that any agreement with Woodside to combine its oil and gas assets in Australia, North America, and Africa might result in a distribution of Woodside’s shares to BHP shareholders. A merger with Woodside is one of the options being considered by BHP as part of a strategic evaluation of the company’s oil and gas business and its long-term portfolio.

BHP’s oil and gas unit, according to Bernstein analysts, might be worth $13 billion. Woodside has a market capitalization of $15 billion.

BHP’s move to examine its petroleum business comes at a time when big mining corporations are under pressure to reduce their reliance on fossil fuels and conform with the Paris climate agreement’s aims.

BHP’s biggest substantial corporate reform since 2014, when it emerged a collection of undesired businesses to form South32, would be a spinoff of its oil division. Petroleum output has fallen from 235 million barrels in 2013 to roughly 103 million barrels in the 12 months to June, or 280,000 barrels per day, due to aging fields and the sale of BHP’s loss-making US shale division in 2018.

BHP has also put its final remaining thermal coal mine up for sale, as CEO Mike Henry aims to focus on greener commodities. Fossil fuels account for around 12% of the company’s revenue. Following its strategic review, Credit Suisse predicted that BHP would sell its entire fossil fuel business, including its petroleum division.

“Petroleum no longer fits within BHP’s portfolio or future-facing strategy. After waiting too long to divest thermal coal, and now having to resort to selling for cents on the dollar, BHP should know it’s better to exit petroleum sooner rather than later,” said Saul Kavonic, an analyst at the Swiss bank.

BHP’s selling of its petroleum business, according to Jefferies, will benefit the company’s environmental, social, and governance efforts while also speeding up its shift to commodities like copper, nickel, and potash.BHP is also expected to authorize spending of between $5.3 billion and $5.7 billion to bring a massive Canadian potash mine into production when it releases its annual results on Tuesday. The findings from London will be presented by Henry.

Geraldine Slattery, BHP’s global head of petroleum, traveled to Perth over the weekend for talks with Woodside’s acting chief executive Meg O’Neill, according to the Australian Financial Review, which first reported the merger talks. A transaction would provide a portfolio of cash-generating assets in Australia and the Gulf of Mexico for Woodside, which is listed in Sydney. It might also help BHP get approval for its $16 billion Scarborough project, in which it has a share.

Following news of the talks, Woodside’s stock dropped 4.4 percent to a 10-month low. Because of their investment mandates, investors of BHP’s London-listed shares may be required to sell any Woodside stock they acquire in a merger, according to traders. The shares of BHP were down 0.8 percent on the Sydney Stock Exchange.