Upbeat economic news from mainland Europe and China and rising oil prices lifted London shares above a key threshold on Wednesday.
The FTSE 100 Index topped 6,700 to stand 61.88 points up at 6748 as eurozone service sector figures came in only marginally lower than June's four-year high.
It helped investors to shrug off disappointing services numbers in the UK, which showed lower-than-expected growth in July against June.
Connor Campbell at Spreadex said: "That UK services PMI miss brings the figure to a 16 month low.
"More importantly, combined with the performance of the manufacturing and construction PMIs, it points to second quarter GDP of 0.6%, not the preliminary 0.7% reported last week."
Services data from Beijing also eclipsed the UK numbers, showing the Chinese service sector racking up its quickest growth in 11 months.
The improvement in the Caixin China PMI Services index helped US light crude oil to rise more than 1% to US$46.40 a barrel.
That boosted oil majors such as BP (LON:BP.) and Royal Dutch Shell (LON:RDSB), which rose 5.95p to 396.35p and 28p to 1873p respectively.
US markets were tipped to open mixed on Wednesday with Walt Disney shares set to drag the Dow Jones Industrial Average lower after missing revenue estimates.
Attention also focused on Apple, whose shares risked falling for a sixth day in a row on growth concerns.
Financials dominated the companies reporting on Wednesday in London.
Asia-focused bank Standard Chartered (LON:STAN) ticked up 36.3p to 988.9p as it slashed its dividend by half but reported restructuring progress.
Insurer Legal & General (LGEN) increased 6.9p to 270.3p on news of an 18% rise in operating profit to £750mln and a 19% rise in the interim dividend.
Sausage skin maker Devro (LON:DVO) sizzled 21.75p to 320.5p as the sausage skin maker reported firm prices and rises in sales volumes in several key markets.
In the small cap space, African Potash (LON:AFPO) saw shares rise for the second consecutive day, by 0.12p to 0.52p.
The company announced a deal yesterday with Comesa, a free trade union of twenty African countries, to provide 500,000 tonnes of fertiliser over three years.
Elsewhere, Rosslyn Data Technologies (LON:RDT) revealed it had won a contract with an unnamed Fortune 500 company that will replace its own analytics platform with Rosslyn’s RAPid cloud-based system.
Rosslyn’s chief executive Charles Clarke called the deal an “excellent step forward” and shares climbed 1.62p or 14% to 12.88p.
Meanwhile, Stratex International (LON:STI) expects to complete construction of the Altintepe gold mine in Turkey imminently with the first gold pour on track for the end of next month. Shares rose 0.25p to 1.62p.
Conversely, Galileo Resources (LON:GLR) led the fallers after the company completed a placing of 31mln new shares at 1.2p to raise £375,000 to pay licence fees due on its US properties. Shares dropped 0.18p to 1.25p.
Spirax-Sarco Engineering faded 225p to 3164p on news of slowing growth rates in its global markets, which include aerospace and other heavy industries.