The blue-chip FTSE 100 index was up after touching 6,757.96, its highest since last August.
It is up more than 16% from its post-Brexit trough, though only 12% in dollar terms because of a sharp decline in sterling.
The market also got some help from data showing Britain’s economy picked up during the second quarter — which concluded with the vote to leave the EU — helped by the biggest upturn in industrial production since 1999.
Basic resources stocks were the top sectoral gainers, with the UK mining index gaining 1.6% after recent losses.
ITV led the FTSE 100 index higher, gaining 8.3% at one stage, after the company forecast advertising revenues ahead of market expectations.
George Salmon, equity analyst at Hargreaves Lansdown, welcomed the company’s strengthened balance sheet and lower net debt, adding its dividend was also an attraction.
Shares in Taylor Wimpey rose 4.1% after Britain’s third-largest housebuilder said the Brexit referendum has had no meaningful effect on its performance in the last month.
Other property-related stocks also rose.
Barratt Developments, Persimmon and Berkeley gained 3.2% to 4.6%, while mid-cap company Rightmove advanced 7% after saying it was confident in its outlook despite Brexit.
However, analysts stayed cautious on the sector’s outlook.
“Investors could remain shy of UK real estate shares given that risks of recession are difficult to assess in the shortest term,” Ipek Ozkardeskaya, analyst at London Capital Group, said.
“Uncertainties will certainly keep the UK’s housing market at distressed territories until we have more clarity on Brexit-related capital and human flows.”
Outsourcing group Capita fell 2.3%, the top faller in the FTSE 100, after saying it was seeing some delays in decision-making in the short term due to Brexit.
Earnings announcements from companies including LVMH Moet Hennessy Louis Vuitton, Telecom Italia and Banco Santander helped push the Stoxx Europe 600 Index up as much as 0.8% before it pared its gain to 0.4% amid a slide in oil.