The FTSE 100 Index rose 29.8 points to 5748.7, with Royal Dutch Shell, Costa coffee owner Whitbread and Unilever shares pushing higher after pleasing results.
The Dow Jones Industrial Average was up 0.4% as the London market closed after the highest homes sales for nearly two years helped reassure investors about the health of the world's largest economy.
But markets in Europe were mixed after a survey revealed that economic sentiment in the eurozone fell more than expected in April.
The pound rose on currency markets as it regained some of the losses it suffered on Wednesday when the UK's return to recession made another round of quantitative easing seem more likely. It was up at 1.62 against the dollar and at 1.22 against the euro. London's blue chip shares index has now recouped nearly all of the losses it sustained on Monday when political uncertainty in the eurozone triggered a rout.
The gains in recent days have been driven by strong corporate earnings in the US, but yesterday there were a number of high profile successes in London.
Royal Dutch Shell reported a profits haul of 7.66 billion US dollars (£4.75 billion), up 11% on a year ago and about 10% better than the consensus market forecast.
Shares were 3.5% or 77.5p higher at 2266.5p, while BP benefited ahead of its own figures on Tuesday, rising 12p to 444.3p.
Hellmann's and Knorr firm Unilever added 3% or 56p to 2135p after first quarter underlying sales rose by a bigger than expected 8.4%.
Sales volumes rose 3.5% and it said it had successfully passed on rising costs to consumers in the Americas and emerging markets. And there was a rise of 6% for Whitbread after the Costa coffee, Premier Inn and Beefeater restaurants business announced it grew full-year profits by 11% to £320.1 million.
But pharmaceuticals firm AstraZeneca blamed a "loss of exclusivity" on its products for a 38% decline in first quarter pre-tax profits to 2.1 billion US dollars (£1.3 billion).
It scaled back earnings forecasts and said chief executive David Brennan would step down in June after six years at the helm. Shares were off 6% or 174.5p at 2666.5p.
Among the Footsie risers were Whitbread up 112p at 1921p, Randgold Resources ahead 275p at 5620p, and Weir Group up 60p at 1720p.