Defence company BAE Systems has signed a £1.9bn contract to supply training jets to Saudi Arabia.
BAE says the deal will save 218 jobs at its East Yorkshire factory were Hawk trainer jets are made.
The workers will be making the planes for at least two years, but the union Unite told the BBC 205 jobs were still at risk.
The deal follows a 2006 deal with Saudi Arabia for 72 Eurofighter typhoon aircraft, worth £6bn.
SPA, the Saudi state news agency, quoted an official who said the new contract would help pilots "use fourth generation jet fighters in full professionalism and efficiency".
Planes have been made at the Brough factor for just under a century.
Earlier this month Dick Olver, chairman of BAE, was forced to apologise after it named a plan to close the factory after the Battle of Bosworth, in which the Duke of York was defeated by Henry Tudor.
At the time Dick Olver, BAE chairman, said: "I express regret if that name has caused concern. I apologise. I will talk to Ian [King, BAE chief executive] about it."
In 2011 BAE said up to 3,000 UK jobs would be cut, and workers have claimed the company is not doing enough to help them find employment elsewhere or within the company.
Amnesty International UK Campaigns Manager Kristyan Benedict voiced serious concerns over the BAE deal, pointing out that the Saudi air force has committed atrocities in the past.
He said: “This new BAE deal is extremely concerning given that Saudi Arabia’s air force has committed serious human rights violations in recent years.
“In 2009, Saudi Arabia deployed its army and air force in northern Yemen. Aerial bombardments killed hundreds of people and caused widespread damage to homes and a massive displacement of inhabitants.
“The UK Government must rigorously investigate into whether military aircraft, other weapons and their on-going in-country military support to the Saudi Arabian armed forces have been used in violation of international humanitarian law.
“The UK must also ensure that it does not authorise the transfer of weapons to Saudi Arabia, or any country, where there is a substantial risk that these weapons may be used to commit human rights violations.”