BOSSES behind a huge North Yorkshire mine have revealed a multi-billion dollar fertiliser deal.

Sirius Minerals says it has extended an agreement with a US-based company to send polyhalite across the Atlantic.

The firm will annually dispatch 1.5 million tonnes for seven years, which could be extended further across two five-year periods.

Officials told The Northern Echo the deal is the biggest and longest out of all of Sirius’ existing sales agreements.

The company says the contract is a revision of a previous agreement to send at least 500,000 tonnes annually over an initial five years, adding the potential new 17-year alliance represents a multi-billion dollar deal between the UK and the US.

The polyhalite will come from Sirius’ £2bn York Potash Project, based three miles outside Whitby, which will be the UK’s first potash mine in 40 years when it is built.

Sirius says the development, approved by the North York Moors National Park Authority earlier this year, will create more than 1,000 direct jobs by tapping into the world’s largest and highest grade of the polyhalite.

Building work on the mine could start later this year.

Reacting to the US deal, Chris Fraser, Sirius’ managing director and chief executive, said: “We are delighted with this further show of confidence from our North American partner and look forward to sharing successes together for decades to come.

“Like many in the industry, our customers understand the value of polyhalite, its multi-nutrient qualities and the fact it can help farmers get the same or better yields more economically.”

Mr Fraser added the US contract means Sirius now has agreements in place to send 3.1 million tonnes of polyhalite to customers every year, with a further 4.8 million tonnes lined up for other annual commitments.

Alongside its US tie-up, the company has an agreement with a Central American fertiliser distributor for 250,000 tonnes of polyhalite a year, and a deal with a South American distributor for 300,000 tonnes a year over seven years.

Sirius hopes to extract 13 million tonnes of polyhalite every year from its mine, from an overall defined store of 2.66 billion tonnes.

The firm, which has already spent about £125m on the development, will sink mine shafts at the former Doves Nest Farm, before shifting the mineral underground on a conveyor belt to a handling site at Wilton, near Redcar, for granulation, storage and distribution.

Redcar and Cleveland Council’s regulatory committee previously approved the mine and the transport system, with a decision on an adjoining harbour, earmarked for Bran Sands, on the mouth of the River Tees, to load ships carrying exports, expected from the Government next summer.