The FTSE 100 opened higher, up 0.26% or 13.87 points to 5,289.31, supported by M&A activity in the resources sector.
Cairn Energy's shares advanced 3.57% to 485p on news it has sold a 51% stake in its Indian business to Vedanta for $8.5bn (£5.4bn). The sale will result in a cash windfall for Cairn shareholders. Vedanta shares also rose on the news by 2.63% to £21.07.
Meanwhile, Aviva climbed 1.94% to 394.9p after outlining its reasons for rejecting RSA's bid for its general insurance businesses in the UK, Ireland and Canada.
However, RSA is one of morning's biggest fallers, down 1.26% to 125.8p. Other casualties include Anglo American, down 1.71% to 23.30, while RBS dipped 0.47% to 46.75p
On Wall Street, the Dow Jones closed down 0.16% or 16.80 points to 10,303.15 despite positive economic data.
Retail sales figures for July showed a rise on the previous month, but suggested consumers remain uncertain about the future.
The news impacted consumer stocks, with Home Depot down 1.09% to $27.31 while Walt Disney dropped 0.91% to $33.68.
In Japan, the Nikkei 225 fell 0.6% or 55.23 points to 9,198.23 as data showed the country's economy slowed sharply in April-June from the previous two quarters.
Caring for children and elderly relatives
Similar to June 2007
Square Mile’s series of informal interviews
Fine reduced to £60,000
Two roles created