Ocado has officially been launched into the FTSE 100 after a year of unprecedented deal-making by the company.
The retail business has been selling its technology to international partners, culminating in a transformational deal with US retailer Kroger earlier this month.
On Wednesday the London Stock Exchange confirmed that Ocado will be promoted into the FTSE 100, to be made effective after market close on June 15.
Scandal-hit G4S, which recently posted a fall in revenue, will be demoted into the FTSE 250 index, alongside Mediclinic International.
London’s blue-chip index closed the session 0.75% or 56.93 points higher at 7,689.57.
Trading was mixed across Europe, as the Cac 40 in France was down 0.2%, but Germany’s Dax rose 0.93% in the afternoon.
In currency markets, sterling was up 0.23% against the dollar at 1.328. Against the euro, the pound fell 0.75% to 1.139.
Oil prices surged following reports that the Organisation of the Petroleum Exporting Countries will keep supply levels steady. Data also showed exports from Iran fell in May, after the US announced it would impose sanctions.
Towards the end of trading, Brent crude jumped 2.67% higher to 77.380 US dollars a barrel.
David Madden, market analyst at CMC Markets, said: “The oil market has recovered a little in the wake of the severe sell-off at the back end of last week.
“There is still talk that Saudi Arabia and Russia will increase supply, but that hasn’t stopped the bulls today.”
In UK markets, the Royal Bank of Scotland (RBS) became one of the biggest fallers on the FTSE 100 after it emerged its finance director Ewen Stevenson had resigned.
RBS chief executive Ross McEwan credited him with helping resolve a number of the bank’s “major legacy challenges” during his tenure. Shares closed for the day down 1.85% or 5.1p at 271.1p.
SSE became the last energy firm from the Big Six to hike bills, prompting a minister to call on consumers to “vote with their feet”.
SSE blamed wholesale price increases and Government policy for the increase in its tariffs.
The group is increasing electricity and gas bills by an average of 6.7%, or £76 per year, in a move affecting 2.36 million customers. Shares closed the day down 3.5p at 1,371.5p.
De La Rue’s shares climbed after the firm posted a rise in profits for the year, despite the company’s “disappointing” failure to secure the contract for manufacturing the UK’s new post-Brexit passports.
Pre-tax profits nearly doubled from £58.2 million to £113.6 million in the year ended March 25, with revenues up by 7%, from £461.7 million to £493.9 million. By the market close, shares were up 3.38% or 17p to 520p.
London-focused housebuilder Telford Homes celebrated record annual revenues and soaring profit on the back of continued demand in the capital.
Telford’s pre-tax profit was up 35% to £46 million in the year to March 31, while revenue rose from £291.9 million to £316.2 million. However, shares fell 2.5p to 456p.
The biggest risers on the FTSE 100 were Royal Dutch Shell up 48.5p to 2,675.5p, BP up 11.5p to 570.5p, BHP Billiton up 33.2p to 1,708.8p and GlaxoSmithKline up 27.6p to 1,525.2p.
The biggest fallers on the FTSE 100 were G4S down 5.1p to 271.1p, Royal Bank of Scotland down 3.9p to 276.1p, Melrose down 2.5p to 233p and International Airlines Group down 6.8p to 684.8p.