The FTSE 100 has ended three straight days of losses to move 0.9% higher, returning to levels last seen at the end of May.
The blue chip rose above 6,660 for the first time since 30 May after strong earnings releases from the likes of Easyjet and ARM Holdings buoyed investor confidence.
Easyjet led the index higher, rising 7% to £14.28 after reporting a better-than-expected 10.4% jump in Q3 revenue. The stock had earlier been up by as much as 9%.
ARM, meanwhile, rose 5% to 942p after revealing first half revenue rose 27% to £341.5m.
Other stocks on investors' watchlist included GlaxoSmithKline, which said in its own Q2 earnings statement that is expects to see "some impact" on its China operations as a result of an ongoing bribery investigation.
The stock pared initial gains to stand up 0.6% at £16.83 by the early afternoon.
In Europe, German PMI data which showed the economy is once again expanded helped prop up sentiment, overriding earlier weaker data coming out of China.
Germany's DAX rose 1.1% to 8,402, while France's Cac 40 rose 1.2% to 3,971. The improving data was accompanied by a rise in German 10-year yields: benchmark bund yields rose to 1.6%, up from 1.55% yesterday, according to Tradeweb.
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