By midday the FTSE 100 was sharply higher, up 1.5% at 6,936.05, mining firms contributing to the rally on hopes of progress on trade between the US and China.
Sterling was relatively stable as Theresa May looks for concessions from the EU to get a revised version of her Brexit deal through.
LARGE AND MID CAP RISERS AND FALLERS
Bourse operator London Stock Exchange announced it would acquire a 4.9% interest in Belgian settlement services provider Euroclear for €278.5m. The shares advanced 0.9% to £45.72.
Hungarian low-cost carrier Wizz Air recovered earlier losses to trade up 0.4% to £30.61 as it reported a sharp fall in third-quarter profit partly owing to higher fuel costs.
SMALL CAP RISERS AND FALLERS
Performance materials group Low & Bonar dropped 11.1% to 16.1p as its annual losses more than doubled and it launched a £54m discounted share issue to strengthen its balance sheet.
Waste-to-product group Renewi gained 4% to 28.75p on announcing that it expected to deliver full-year results in line with its expectations, despite a softening performance at its commercial division.
Mobile payments group Mi-Pay shed 5.2% to 9.2p after it forecast another annual operating loss, albeit narrower, despite boosting sales.
Entertainment marketing group Reach4entertainment added 1.9% to 1.02p on news it had agreed to acquire 50% of Gary Neville-backed sports content supplier Buzz 16 Productions, for an undisclosed sum.