The FTSE 100 Index is up 22.8 at 4874.5 after an hour's trading.
The London market appears to be making up for lost ground.
The Footsie slumped 83 points yesterday following a gloomy start on Wall Street.
But the Dow Jones and Nasdaq staged a late rally last night after bullish updates from Procter & Gamble and Motorola.
There was also speculation that Microsoft was gearing up to announce it was likely to beat its fourth-quarter forecast.
In London trading, Vodafone is up 1¾p at 99p; mmO2 has gained ½p at 39¼p; and Cable & Wireless is up ½p at 195p.
Chip designer ARM Holdings is up 7¾p at 173¼p despite being demoted from the top flight FTSE 100 Index last night. It will join the FTSE 250 on June 24.
Heavyweight stocks providing support for the market include AstraZeneca, up 31p at £28.32; and Shell, 4½p stronger at 500p.
Dairy Crest is down 10½p at 536p despite posting final figures ahead of forecasts and pledging to boost production. Most analysts attribute the drop to profit-taking.