Meanwhile, Sunak delayed the announcement of a keenly awaited plan for repairing the country's public finances until Nov. 17, two-and-a-half weeks later than previously planned. The news briefly raised British borrowing costs, but there was no repeat of the panic bond selling caused by his predecessor Liz Truss's tax-cutting plan.

"Investors are mindful that it was the unnecessary rush to announce big tax cuts which caused such tumultuous times for the Truss administration and what they crave now is caution and stability," said Susannah Streeter, senior investment and markets analyst at Hargreaves Lansdown. "The premium slammed on UK assets by reckless policies of his predecessor appears to be slowly lifting, but hefty challenges for team Sunak remain."

UK financial markets were roiled earlier this month, with the pound hitting 2008 lows after Truss announced a series of unfunded tax cuts in September. Among companies that reported results, Standard Chartered fell 5.1% despite a 40% surge in profit after the Asia-exposed bank said the outlook for China's real estate sector remains "challenging".

Barclays slipped 0.3% after it set aside a hefty charge for potentially soured loans, highlighting a tough outlook for borrowing. Reckitt Benckiser dropped 4.1% after the consumer goods company reported a decline in sales volumes in the third quarter and warned of pressure on consumers globally.