BHP Group is reportedly in talks with Canadian fertiliser firm Nutrien over a potential partnership for the development of the Jansen potash project in Canada.

The two companies are discussing multiple options for the mine. Among these options include Nutrien purchasing a stake or becoming an operator and selling the potash through its channels, Bloomberg News reported citing sources.

BHP has already invested $4.5bn in the project and completed digging two 1,000m-deep shafts.

However, the project is due to receive approval for construction. It also faced opposition from investors.

The Australian miner plans to announce its decision this year on whether to approve another $5.7bn on the project to start production.

BHP CEO Mike Henry earlier said: “We continue to like potash. We think the long-term demand and supply fundamentals for potash are attractive.

“We’ve always said we’re open to partnering, but the project doesn’t need a partner to proceed.”

The Jansen project is a proposed underground potash development project in Saskatchewan. It has an estimated mine life of more than 50 years.

Expected to be one of the world’s largest potash mines once completed, the project will produce around eight million tonnes of potash a year.

BHP was granted environmental impact statement approval for the Jansen mine in February 2011 and was originally scheduled to begin first production by 2015.

According to estimates, the mine holds 3,250 million dry tonnes of indicated resources graded at 25.4% potassium oxide.