Investors welcomed the deal on Wednesday morning after a volatile six weeks for the financial markets since the conflict first began.
The price of oil plunged and global stock markets recovered sharply after the US and Iran agreed a two-week ceasefire.
The conditional ceasefire deal includes reopening the important Strait of Hormuz waterway.
Traders and investors welcomed the deal on Wednesday morning after a volatile six weeks for the financial markets since the conflict first began.
London’s FTSE 100 index of major firms jumped by as much as 2.6% at the start of trading as a result.
It came as the price of benchmark Brent crude oil slid by 14.3% to 93.6 US dollars (£69.78) a barrel as a result.
Nevertheless, prices remain significantly higher than before the conflict began, when Brent had sat at around 70 dollars a barrel.
Petrol and diesel prices for UK motorists have shot higher as a result.
The ceasefire followed threats by President Donald Trump on Tuesday that “a whole civilisation will die” unless Tehran met his demands.
Less than two hours before his deadline passed for Iran to agree a deal, the US president said he was suspending his threat to widen the military offensive to power plants and bridges, subject to the strait reopening.
Stock markets roundly welcomed the news, with key Asian indexes such as Japan’s Nikkei 225 and South Korea’s Kospi rising by more than 5%.
European markets also opened positively, with the FTSE 100 up by 268.28, or 2.59%, to 10,617.07 points after the opening bell, taking it to its highest level for around a month.
The FTSE 250 index was, meanwhile, up 3.75%.
