The FTSE 100 Index soared past the 5600 level today as stock markets worldwide rallied ahead of Tuesday's key meeting on interest rates by the US Federal Reserve.
The FTSE 100 Index raced 94.1 points higher to 5602.5 - up 1.7% - marking its first close above 5600 since the end of April.
Wall Street's Dow Jones Industrial Average rose more than 100 points, with similar gains across Europe as the Cac 40 in France closed up 1.8% and Germany's Dax finished 1.4% higher.
Markets in the UK and US have not ruled out a Fed move to reignite flagging growth in the world's biggest economy when it reveals its interest rates decision tomorrow evening.
There is a growing expectation the Fed's rate-setting committee might relaunch moves to buy securities and mortgage bonds in an effort to further stimulate the struggling economy.
But in currency news, the pound weakened after gloomy economic indicators, with Bank of England data showing the worst August for mortgage lending in a decade.
Sterling slipped 0.5% to US$1.56 and 0.7% to €1.19.
One of the biggest moves in the FTSE 100 Index came from oil giant BP after the US coastguard and the company itself declared that the Gulf of Mexico well had been permanently sealed.
Shares rose 8.3p to 411.4p, but the crisis is far from over for the oil giant as it faces the financial impact of clean-up costs, fines and civil lawsuits.
Lloyds Banking Group was also in the spotlight after announcing that chief executive Eric Daniels plans to retire in a year's time. Shares lifted 2.1p to 77.4p as the news removed uncertainty surrounding the top post.
Defence giant BAE Systems was another riser as it announced a multi-million pound deal to buy part of an American intelligence business. The group's shares rose 4.6p to 333.8p, or 1%.
Supermarkets featured on the risers board after analysts at Bernstein lifted price targets across the food retail sector, citing rising food price inflation as a support.
Morrisons rose 7.5p to 306.3p, Tesco was 8.9p dearer at 437.5p and Sainsbury's added 8.7p to 394.1p.
One of the biggest rises in the FTSE 250 Index came from Brit Insurance after the sponsor of the England cricket team said on Friday evening that it had recommended a takeover proposal from private equity firms Apollo and CVC. Brit moved 40.5p ahead to 1028p.
Fellow second tier stock JD Sports Fashion joined Brit in making advances, up 13% or 97p to 823p, ahead of its interim results tomorrow, which are expected to confirm a resilient first half from the sportswear retail group.
The biggest Footsie risers were Carnival up 118p to 2489p, Rexam ahead 11.2p to 313.8p, Intertek up 65p to 1853p and Hammerson up 12.5p to 395.3p.
The biggest Footsie fallers were Resolution down 4p to 243.2p, Aggreko off 23p to 1590p, TUI Travel down 1.2p to 220.5p and Cairn Energy off 1.6p to 426.8p.