Source: Sharecast
The FTSE 100 was called to open around 37 points higher.
The US president announced the extension to 6 April on Truth Social on Thursday.
In a brief post, he said: "As per Iranian Government request, please let this statement serve to represent that I am pausing the period of Energy Plant destruction by 10 Days to Monday, April 6, 2026, at 8 P.M., Eastern Time.
"Talks are ongoing and, despite erroneous statements to the contrary by the Fake News Media, and others, they are going very well."
Trump first announced on Monday that the US was postponing "any and all" military strikes against Iranian energy infrastructure following "very good and productive conversations" about a resolution to the hostilities in the Middle East.
The U-turn came just two days after he threatened to "obliterate" the country’s power plants if it did not reopen the Strait of Hormuz within 48 hours.
Ipek Ozkardeskaya, senior analyst at Swissquote, said: "With or without the US in the mix, attacks continue in the Middle East. Gulf countries have exchanged strikes throughout the week, and traffic through the Strait of Hormuz remains very limited.
"Iran’s so-called ‘gift’ to Trump was the transit of 10 oil tankers this week - compared to roughly 100 ships that pass through this strategic waterway per day in normal times.
"As such, the extension of Trump’s ceasefire does not necessarily point to material progress toward peace or an improvement in oil flows. However, it appears to reassure investors that the weekend could be less volatile than feared, in the sense that the US may refrain from further escalation after the market close."
On home shores, figures from the Office for National Statistics showed that retail sales fell less than expected in February.
Sales were down 0.4% following a revised 2% increase in January, and versus expectations for a 0.8% decline.
Supermarkets' sales volumes fell back following a rise in January, the ONS said. Meanwhile, non-store retailers' volumes also fell, with retailers suggesting that consumers brought forward their spending to January to maximise on discounting during the period.
Hannah Finselbach, senior statistician at the ONS, said: "Retail sales rose in the three months to February, with online shops seeing strong sales and art dealers also faring well.
"These were partially offset by a weak period for clothing stores."
In corporate news, Metlen Energy & Metals said its full-year results will be delayed by nine days after PricewaterhouseCoopers asked for more time to complete its audit of the first financial statements of the firm as a dual-listed company in the UK and Greece.
It also reiterated earnings guidance of €750m. Metlen will now publish its financial results for the year to December on 9 April.
Drugmaker GSK said the European Medicines Agency will review its marketing authorisation application for the use of bepirovirsen, an investigational antisense oligonucleotide, in the treatment of adults with chronic hepatitis B.
GSK said the regulatory submission to the EMA was based on positive results from its B-Well 1 and B-Well 2 Phase III trials - both of which met their primary endpoint, with bepirovirsen demonstrating a "statistically significant and clinically meaningful" functional cure rate.