The FTSE 100 opened higher, up 0.46% or 24.52 points to 5,337.14, on encouraging news from the oil sector.
Investors also responded positively to results of European stress testing which saw all the major banks pass.
BP rose 2.68% to 409.3p on news embattled BP chief executive Tony Hayward is expected to resign tomorrow.
Elsewhere in the resources sector, Tullow Oil says it has found a new oil field, causing its shares to jump 5.43% to £12.43.
However, it was a mixed picture for the UK's banking stocks as Barclays increased 2.68% to 309.5p, while Standard Chartered was down 0.25% to £18.19.
In Europe, banking shares drove the major indices higher. France's CAC 40 rose 0.42% to 3,622.23 led by Societe Generale, BNP Paribas and Credit Agricole, while Germany's Dax was up 0.32% to 6,186.28 topped by Commerzbank.
On Wall Street, US stocks made further advances as investors responded positively to European bank stress test results.
The Dow Jones closed up 0.99% or 102.32 points to 10,424.62.
Despite posting a 12% rise in second quarter profits, McDonald's was the biggest faller, down 2.1% to $69.90.
In contrast, Verizon rose 3.78% to $28.02 as second quarter losses were not as bad as expected.
In Japan, the Nikkei gained 0.77%, or 72.70 points, to 9,503.66 as hopes for robust corporate results from firms including Sony and Toyota buoyed the market.
Two global vehicles
'Further plug advice gap'
Must appoint separate CEOs and boards
Advisers do come out well
Will report to Mark Till