The FTSE 100 limped up 1.03 per cent to day recovering after early jitters.
The index closed up 56.30 to 5,527.00, above the 5,500 barrier it has been battling with in recent weeks.
Petrofac led the gains up 7.26 per cent, while Group 4 Securicor (G4S) was up 5.91 per cent both buoyed by expectation-breaking half-year results.
Cairn Energy was up 5.68 per cent and miner Eurasian climbed 4.80 per cent.
London Stock Exchange Group rose 3.89 per cent.
Enterprise Inns was down 4.51 per cent, insurer Admiral Group dropped 3.13 per cent and Carphone Warehouse fell 3.07 per cent.
Next dropped 2.78 per cent and Hammerson fell 2.65 per cent.
In New York, the Dow Jones has opened positively rising 0.32 per cent by 16:56 BST.
David Jones, chief market strategist at IG Index, said: The focus was on the oil sector today with good first half numbers from a couple of constituents - Tullow Oil and Petrofac reported a jump in profits of 181 per cent and 57 per cent respectively.
"This, combined with renewed interest in the mining sector after yesterdays drops meant the UK index remained well supported for much of the day."
He added: "A positive start by the USA has also helped keep London positive as the day has worn on. The next day or so could prove key for the UK market to see if this strength is set to continue.
"This month has seen the FTSE run out of steam ahead of the 5550/70 area once already and the temptation to book some profits on the back of the past weeks gains could prove too tempting for traders as August draws to a close."