The FTSE 100 index notched up a new 14-month high as markets rose on hopes of a strong third quarter earnings season.
The Footsie marched towards closing levels last seen in August 2002, standing 51.3 points higher at 4362.3 by the close of trading.
The Dow Jones Industrial Average gave the UK's top flight shares a late boost, standing about 91 points up by London's close.
Analysts speculated about whether the upbeat mood could push the strong-looking Footsie through the 4500 barrier, saying that little apparent desire for profit-taking suggested more to come on the upside.
Among the financials, insurer Royal & Sun Alliance held its own throughout the day to close at the top of the Footsie risers, 4.75p up at 95p.
Prudential ended the day in third place, 21.5p the better at 458.75p after a broker upgrade,
In a positive session for the sector, Norwich Union owner Aviva lifted 8.5p to 497.5p, Legal & General rose 1.75p to 101.25p and Friends Provident gained 2.25p to 140p.
The market's confident mood was reflected by buying interest in a number of heavyweight stocks, with oil pair Shell and BP up 6.25p and 8p to 396.25p and 441.75p respectively.
Allied Domecq provided the market with its only major blue-chip announcement after the drinks giant said it had pulled out of the running to buy Australian company Peter Lehmann Wines.
With Allied selling its 14% stake in Peter Lehmann to rival bidder Hess, shares gained more than 4% or 16.25p to 387p.
The day's biggest gainers were Royal & Sun Alliance, up 4.75p at 95p, BHP Billiton advancing 23p to 475p, Prudential rising 21.5p to 458.75p and Allied Domecq 16.25p ahead at 387p.
Biggest losers included mm02, weakening 1.75p to 62.75p, Amersham down 11.5p to 748.5p, Exel off 7.5p at 712.5p and Hilton Group 2p lower at 197.75p.