Encouraging Chinese growth figures helped blue-chip shares make gains amid renewed hopes that America will continue its vast stimulus drive.
The FTSE 100 Index was 46.4 points higher at 6622.6 as official figures showed China grew at 7.8% in the third quarter from a year earlier - up from a two-decade low of 7.5% the previous quarter.
While the pick-up was widely expected, it helped underpin confidence, with markets also relieved over America's 11th-hour debt deal.
France's Cac 40 and German's Dax posted gains though on Wall Street, the Dow Jones Industrial Average was flat as the extent of the damage done to the US economy by the partial government shutdown began to be felt.
Markets remain cautious over the prospects for a further political tussle in Washington, when the next deadlines are due to find a permanent resolution to its fiscal issues.
But the recent debt drama has increased expectations for the US Federal Reserve to push back any plans to taper quantitative easing until after 2013 - leaving America's currency to continue its recent soft performance.
Sterling held on to a high of 1.62 US dollars while it was also flat against the euro at 1.18 euros.
Among stocks, Asia-focused insurer Prudential topped the blue-chip risers board with a 4% gain following an upbeat statement overnight from its rival AIA.
Asia-based AIA posted record quarterly results after new business rose by 26%, which bodes well for Pru, given its exposure to the region. Pru shares added 50p to 1264p.
Miners were also making strong gains after the Chinese economic data, which boosted demand hopes from the world's second-biggest economy.
Silver miner Fresnillo led the sector higher, up 36p to 988.5p, while Glencore Xstrata also improved with a 4.4p gain to 334.9p.
But bookmaker William Hill was the worst performer on the FTSE 100 after being hit by a downgrade from brokerage JP Morgan. Its shares were 13.3p lower to 403.5p.
Royal Bank of Scotland was also knocked by a broker downgrade, with Investec expert Ian Gordon warning it expects the part-nationalised lender to slip back into the red in the second half of 2013. Shares were down 4.2p to 372.7p.
Barclays joined it in the red - down 0.4p to 277.8p - following fresh Libor rigging concerns after documents revealed new information relating to the scandal in legal papers filed yesterday by care home operator Guardian Care Homes, which is suing the bank over alleged mis-selling of interest rate swaps.
Meanwhile investor appetite for Royal Mail continued unabated as it broke the £5 mark, more than 50% above its privatisation offer price a week ago, closing at 502.5p, a rise of 22.5p during the session.
The biggest FTSE 100 risers were Prudential, up 50p to 1264p, Fresnillo up 36p to 988.5p, Reckitt Benckiser up 146p to 4502p, and Experian up 36p to 1200p.
The biggest FTSE 100 fallers were William Hill, down 13.3p to 403.5p, Anglo American down 21p to 1532p, BSkyB down 12p to 928p and Royal Bank of Scotland down 4.2p to 372.7p.