Saudi Arabia has moved closer to a deal to buy 48 Typhoon fighter jets, UK aerospace giant BAE Systems has said.
A memorandum of intent on the deal was signed after Saudi Crown Prince Mohammed bin Salman met Defence Secretary Gavin Williamson.
BAE said the signing was “a positive step towards agreeing a contract for our valued partner”.
Downing Street said a target of £65bn worth of trade and investment had been agreed during the UK visit.
The preliminary order comes two months after BAE announced around 2,000 job cuts because demand for the Typhoon had slowed.
Analysis: BBC Security Correspondent Frank Gardner
The announcement of this proposed deal is both a shot in the arm for Britain’s aerospace industry and a metaphorical punch on the nose to human rights and anti-war protesters.
They have strongly opposed arms sales to Saudi Arabia both on the grounds of its poor human rights record at home and more urgently because Saudi-led air strikes on Yemen are blamed for the majority of civilian casualties there.
Theresa May is reported to have raised Britain’s concerns on both these issues at a private dinner with the Saudi Crown Prince last night.
But whatever was said has clearly not obstructed a proposed deal worth billions of pounds and thousands of jobs.
Shares in BAE Systems closed up more than 2% in the wake of the announcement although the value of the preliminary deal was not disclosed.
Aerospace, defence and security industry body ADS welcomed this first step in what would be a multi-billion pound deal.
ADS Chief Executive Paul Everitt said: “The Memorandum of Intent is welcome news for BAE Systems and its UK supply chain, which has a 37.5% workshare on the Typhoon programme.”
BAE chief executive Charles Woodburn said: “We are committed to supporting the Kingdom as it modernises the Saudi Armed Forces and develops key industrial capabilities critical to the delivery of Vision 2030.”
Saudi Arabia is undertaking an economic and social reform programme under the recently appointed Crown Prince.