The markets appear to be hoping for Beijing to step in to support the Chinese economy after weak data overnight. The S&P 500 was up 0.3% to 2,842.14 by 4.30pm UK time.
The FTSE 100 was further boosted by a weak pound, which increases the relative value of its overseas earnings. Sterling fell thanks to ongoing Brexit uncertainty and the index of leading UK shares closed up 0.8% at 7,296.95.
LARGE AND MID CAP RISERS AND FALLERS
DIY group Kingfisher dropped 3.6% after it posted flat sales in the first quarter, as a stronger performance in the UK and Ireland was offset by ongoing weakness in France.
Travel company TUI gained 1.8%, despite booking a deeper second-quarter loss owing to a more subdued travel market and the grounding of the Boeing 737 MAX.
TUI also announced that summer bookings so far were down 3%, though the average selling price had risen 1%.
Gambling company William Hill shed 2.6% on announcing that its revenue had grown 2% in the first four months of 2019, as strength in the US and online was offset by more pain on the UK high street.
Cineworld was flat, despite the cinema chain making a slow start to the year, after it also announced the $286.3m sale and lease back of 17 US sites.
Housebuilder Crest Nicholson added 1% after announcing that it had paused its growth strategy to focus on delivering cashflow and dividends.
Catering business Compass climbed 2.9% on lifting its guidance amid growth in North America and its UK defence unit.
Credit checking group Experian gained 1.4% after higher tax and interest charges lowered its annual net profit. The company, however, also delivered organic revenue growth that beat market expectations.
Travel food operator SSP Group gained 0.4% after it booked a 6.2% rise in first-half profit, driven by growth in air passenger numbers and an expanded store footprint.
Thermal energy management and pumping specialist Spirax-Sarco Engineering ticked up 1.3% as its organic sales growth in the first four months of the year remained similar to levels in the second half of 2018.
Automotive fluid systems supplier TI Fluid Systems fell 2.3% on the back of a 2.2% fall in first-quarter revenue.
Molten metal flow engineering group Vesuvius shed 2.5% after it reported flat first-quarter sales, citing a more subdued market.
Paving specialist Marshalls added 1% as its revenue rose 21% in the first four months of the year, amid stronger sales in public and sector and commercial markets.
SMALL CAP RISERS AND FALLERS
Independent utilities provider Yu Group gained 66% as it reported a 77% increase in revenue to £80.6m for the 12 months to 31 December 2018. Yu suffered several accounting and system failings in 2018 which hit the share price and saw the company swing to a loss.