Both the Chinese customers have signed memorandums of understanding for 500,000 tonnes a year.
York Potash now has total commitments for 3.78 million tonnes a year, representing over 75 per cent of phase 1 production.
Chris Fraser, managing director and CEO of Sirius, the company behind York Potash, said: “The global demand for polyhalite continues to grow as customers in key markets around the world increasingly understand the value of this multi-nutrient mineral.
“This provides further support for the York Potash Project and the thousands of jobs it will create in North Yorkshire and Teesside.”
Analyst Richard Knights, at Liberum Capital, said: “Both companies are large scale domestic Chinese businesses, one state owned.
“We fully expect memorandums of understanding for the remaining product to be signed in the near-term, allowing the company to focus on tightening terms of existing memorandums of understanding and framework letters which will put it in a strong position to deliver financing alongside mine approval in the third quarter next year.”
Last week York Potash bought a farm on the site of the proposed potash mine in the North York Moors. Dove’s Nest Farm, near Whitby, includes farm buildings, a farmhouse and three holiday accommodation units.
Mr Fraser said: “There is no greater evidence of our determination to achieve the approval and completion of this project than our purchase of Dove’s Nest farm, the proposed location of the mine.”
The farm will remain occupied and operational in advance of the approvals process being completed for the project.
The project to exploit one of the world’s most extensive seams of potash under the North York Moors National Park has been hit by delays and Sirius is considering submitting a new planning application.
It is also looking at including land outside the national park in the application, meaning that North Yorkshire County Council would be brought into the planning process.
The North York Moors National Park Authority’s chief executive, Andy Wilson, said the decision to extend the boundary could lead to “complications and the increased threat of legal action”.