(Close): The FTSE 100 turned positive at the close boosted by strong gains from leading shares including ARM Holdings and Sky.
The pair's strong results gave their share prices a strong upward push.
The FTSE 100 was up 10.8 at 7,062.93.
Mining shares had weighed on the index earlier but pulled back from their worst losses throughout the session. Rio Tinto shares dropped 2.1% after its first-quarter shipments of iron ore fell below expectations.
Among the other mining giants, Anglo American fell 2% while BHP Billiton was 1.2% lower.
Shares in Sky rose more than 5% after it reported strong third quarter results. Operating profits for the nine months to the end of March rose 20% to £1.025bn.
Arm Holdings - whose designs are used in most smartphones - rose 4% after it reported a 24% rise in first quarter pre-tax profits to £120.5m.
But Primark-owner Associated British Foods was the biggest faller in the FTSE 100, dropping 5.2% after it reported a fall in half-year profits, and warned full-year earnings could be lower.
Despite operating profits at Primark rising 8% to £322m, problems at AB Foods' sugar unit meant group pre-tax profits fell to £213m for the half year to 28 February.
Sugar prices have fallen by about 40% over the past two years and the company's sugar business posted a £3m operating loss for the six-month period.
Carpetright shares jumped nearly 7% after the floor coverings retailer said full-year results would beat expectations, with profits of about £13m now predicted.
However, Shoe Zone shares plunged by nearly 30% after it issued a profit warning. It said first-half revenues and profit would be below last year's results, and added that full-year results were "expected to be below market expectations".
On the currency markets, the pound rose 0.23% against the dollar to $1.4941, but was flat against the euro at €1.3892.
