Britain's top shares extended gains by midday on Monday, led by energy shares after BP permanently killed its deep-sea well in the Gulf of Mexico.
By 1039 GMT, the FTSE 100 was up 63.51 points, or 1.2%, at 5,571.96, rallying on recent falls, albeit in thin trade with volumes at just 21% of their 90-day average.
London's blue chips closed 0.6% lower on Friday, it's third straight session of losses, hurt by weak economic data from the United States and worries over Ireland's finances.
Jimmy Yates, head of equities at CMC Markets, said the FTSE was priming itself for a second attack on the significant 5,610 resistance level, having briefly flirted with it on Friday before falling away sharply.
BP rose 1.7% after the top U.S. oil spill official said on Sunday that the oil major had permanently "killed" the Gulf of Mexico well that ruptured in April and unleashed the worst oil spill in U.S. history.
Energy stocks were the top performers on the FTSE. British oil services and engineering group Amec rose 1.8%, with Liberum Capital initiating coverage on the firm with a "buy" rating.
Miners tracked base metal prices higher, as gold edged close to a record high with investors keen on the commodity as speculation remained of more quantitative easing in the U.S., following the weak data on Friday. Precious metal miner Fresnillo added 0.7%.
FOOD RETAILERS
UK food retailers J Sainsbury, Wm Morrison Supermarkets and Tesco climbed 1.8-2.1% after an upbeat note on the sector from Bernstein.
Testing equipment firm Intertek Group was the top riser, up 3.0% after Seymour Pierce raised its rating to "outperform" from "hold" as a read across from Swiss peer SGS's bullish update.
London's gains were underpinned by U.S. stock index futures pointing to a firmer open on Wall Street.
Banks, which are sensitive to slight changes in risk appetite, were higher, with Barclays, Lloyds Banking Group and RBS.L up from 1.4 to 1.6%, all helped by target price upgrades from JPMorgan Cazenove.
Top FTSE fallers were recent arrivals pump manufacturer Weir Group and insurance buyout vehicle Resolution, which fell 1.4 and 2.1%, respectively, after a strong run prior to their entry to the FTSE 100 at the index's latest reshuffle.
