Saudi Arabia’s Public Investment Fund and Japanese trading house Mitsui & Co. are considering bids for a minority stake in Vale’s nickel and copper operations, people with knowledge of the matter said.

Canada Pension Plan Investment Board, Ontario Teachers’ Pension Plan Board, Mubadala Investment Co. and Qatar Investment Authority are also weighing offers for a stake in the base metal unit, according to the people. Vale is seeking to raise more than $2-billion from the deal, the people said, asking not to be identified because the information is private.

The Brazilian miner has also approached other potential bidders including BlackRock and Singapore sovereign wealth fund GIC Pte to gauge their interest, the people said. It is asking for initial bids in the coming weeks, they said.

The Vale unit could be valued at $20 billion to $25 billion in any transaction, the people said. Vale is seeking to sell at least a 10% stake in the business, though it could considering offloading a larger holding at the right price, the people said.

Shares in Vale rose as much as 4.6% on Tuesday. The stock was up 4.1% at 11:11 a.m. in Sao Paulo, giving the company a market value of about $65-billion.

Deliberations are ongoing, and details of the potential transaction could change, the people said. Representatives for BlackRock, CPPIB, Mitsui, Ontario Teachers, PIF, QIA and Vale declined to comment. Spokespeople for GIC and Mubadala didn’t have any immediate comment.

Vale said in early October that it has hired advisers to assess options for the business as demand for copper and nickel surges due to a global push on electrification and a shift away from fossil fuels. Vale, a major iron-ore supplier, operates nickel and copper mines in countries including Brazil, Canada and Indonesia, its website shows.

Chief Executive Officer Eduardo Bartolomeo said on a conference call last week that Vale is seeking partners that can help accelerate the unit’s growth and could consider an initial public offering at a later date. He has previously outlined “very high ambitions” for the business and said it could become as big as Vale in the future.