Oil-related stocks rallied and pushed the blue-chip index higher, after OPEC agreed a preliminary deal overnight to cut production for the first time in eight years.
The FTSE 100 gained over 1% to 6,926.
Brent crude fell 0.6% to $48.39 per barrel following an initial jump of almost 6% to $49 per barrel.
West Texas Intermediate (WT) crude oil retreated to $46.9 per barrel.
Gold was stable at $1,320 per ounce and copper nudged higher to $4,806 per tonne.
Oil and gas firms Royal Dutch Shell (RDSB), BP (BP.) and general commodities play Glencore (GLEN) were in positive territory.
MAIN NEWS OF THE DAY
Capita (CPI) crashed 26.7% to 698.2p after downgrading its full year pre-tax profit forecast to £535m-£555m. It flagged a slowdown in some trading businesses and continued delays in client decision making, as well as potential litigation concerning a contractual dispute with the Co-op Bank.
UK mortgage approvals fell to 60,058 in August, according to the Bank of England.
BLUE CHIP RISERS AND FALLERS
Alton Towers operator Merlin Entertainments (MERL) achieved 1.3% like for like growth in the 38 weeks to 17 September, but warned of challenging conditions in Florida. The firm said it is piloting a new brand called Little Big City, with the first attraction launching next year in Berlin. Shares dropped 4.9%.
MID CAP RISERS AND FALLERS
The market was impressed with Allied Minds' (ALM) alliance with GE Ventures to jointly identify and commercialise next-generation technologies, as well as invest in new and existing technologies from both pipelines.
SMALL CAP RISERS AND FALLERS
Communications tech firm Imagination Technologies (IMG) fell 3.6% after selling its Pure digital radio business and revealing in-line trading.
TI Fluid Systems, which provides fluid handling systems for the automotive industry, said it will float on London's main market. It generated £1.6bn revenue in the first half of 2016 and €185.6m earnings before interest and tax.
Aerospace services company Strat Aero (AERO) advanced 3.6% after settling litigation from a dispute with the CEO of Aero Kinetics.
Edenville Energy (EDL) raised £500,000, which will be used for the advancement of commercial mining operations at the company's Rukwa site in Tanzania.
Plus500 (PLUS) declined 14% to 644.5p after its founders sold 13% of the business in a share placing to various undisclosed investors at 650p.
Agricultural and distribution business NWF (NWF) warned that first quarter trading was tough as margins were squeezed in its fuel division. Its feeds arm also faced a hit thanks to farmers having less money due to low milk prices.
Newspaper publisher Daily Mail & General Trust (DMGT) nudged higher on an in-line trading update and details of an expanded restructuring programme.
Butcher Crawshaw (CRAW) slumped 4.6% on disappointing half year results. Like-for-like sales were negative, the loss before tax widened and the dividend was suspended. The firm issued a warning that this year's profit could fall 'materially' short of previous expectations.