The owner of a contentious fertiliser mine in North Yorkshire that was mothballed this year has agreed a partnership with two Chinese producers to create a market for the unproven crop nutrient.

Anglo American has signed a memorandum of understanding with Sinochem Fertilizer, the largest distributor of agricultural products in China, and BeiFeng AMP, the country’s third largest player in the sector.

The companies will work together to address potential sales opportunities in China, to hone their marketing strategies and to conduct further research on how polyhalite might be applied to various crops. Tom McCulley, the chief executive of Anglo American’s crop nutrients business, said China was a “key customer” in the miner’s ambition to develop a lead in the polyhalite market.

The Woodsmith mine, near Sneatonthorpe, is set to feature what is thought to be the longest tunnel in Britain at about 23 miles and the deepest mine in Europe. It has promised to produce copious supplies of polyhalite, a rarely used fertiliser, the market for which is unproven. Seventeen miles of the tunnel has been completed and the two mine shafts have depths of 2,600ft and 2,000ft.

However, work on the mine was scaled back dramatically under a restructuring plan set out in May, part of a defence against a £39 billion takeover attempt by BHP, the world’s largest miner. Spending has been reduced to $1 billion over the next three years, from the near-$3 billion that had been set out, which includes $900 million planned for this year. The decision has left about 2,000 jobs in the balance.

First production from the mine had been due in 2027, but is now more likely to be in 2030, Duncan Wanblad, 57, Anglo’s chief executive, has said. The decision to press ahead with the project will depend on the results of a feasibility study that is due to be completed at the start of next year, on repairing the group’s balance sheet and on finding a partner to shoulder some of the cost.

Wanblad, who has championed the project, said in July that there were no plans to shelve it indefinitely, describing the Woodsmith mine as “one of the most exciting projects in the industry today”.

In July, the London-listed miner revealed a $1.6 billion writedown in the value of the mine. The project has been beset by problems with financing before Anglo became involved in 2020 via the £400 million rescue takeover of Sirius Minerals, the original company behind it.

Shares in Anglo American fell 30p, or 1.3 per cent, to close at £22.09.