Upbeat economic data from China and Europe inflated global markets after days of losses on worries over an end to stimulus measures.
Figures showed increased factory output in China, the world's second-biggest economy, while a survey pointed to eurozone expansion in manufacturing and services in August.
The economic cheer helped drive the FTSE 100 Index 50.8 points higher to 6441.6 - up 0.8%.
Markets were also encouraged after policymaker Martin Weale said the Bank may need to top up its £375 billion quantitative easing programme, while minutes of a US Federal Reserve meeting showed uncertainty on whether it will taper stimulus in September or December.
The Dax in Frankfurt and the Cac 40 in Paris also both advanced on encouraging eurozone data.
A monthly composite purchasing managers' index for the 17-country single currency region, which includes both manufacturing and services, hit its highest level since June 2011 as the eurozone's recovery gathers pace.
And better-than-expected Chinese data raised hopes the country's growth slowdown may be easing, with a manufacturing survey showing the sector swinging to growth from contraction a month earlier.
Strong car production figures in the UK likewise boosted sentiment, rising 7% year-on-year in July to 128,873.
In a quiet day for corporate news, c redit card insurer CPP Group's shares plummeted by nearly a quarter after the City regulator said the group and a raft of high street lenders will fork out up to £1.3 billion in compensation for mis-sold credit card and identity theft protection.
The Financial Conduct Authority (FCA) said 13 banks and credit card firms, together with CPP, have agreed to a compensation package that will see CPP contact around seven million customers directly.
Shares in CPP plunged by 24% or 5p to 15.25p, with the settlement coming after CPP was already fined £10.5 million for the mis-selling scandal.
Banking shares shrugged off the mis-selling compensation blow, with Royal Bank of Scotland up 8.3p to 342.4p and Lloyds Banking Group ahead 0.8p to 74.7p despite being listed among those due to offer redress.
Infrastructure group Costain was up more than 3% after reporting a 20% hike in its order book to an all time high of £2.9 billion.
Its shares were 9.25p higher to 290p despite interim pre-tax profits plunging to £3.1 million from £14.7 million.
But shares in support services group Carillion were 5.7p lower to 291.6p after half-year revenues fell 9% to £1.96 billion, driven lower by shrinking its construction arm.
It said while there are some opportunities for medium-term construction growth, the market remains challenging.