The blue-chip FTSE 100 gained 0.3% with Glencore , Rio Tinto, BP and Royal Dutch Shell among the top boosts.
Royal Mail Plc climbed 2.1% to be the top FTSE 100 gainer after it forecast a surge in first-half operating profit.
The domestically focussed mid-cap index rose 0.4%.
Britain’s central bank looks set to keep interest rates steady later in the day with its policy decision due at 1100 GMT as it approaches the end-point of its 895 billion pound ($1.22 trillion) asset purchase programme on the backdrop of rising inflation.
London-listed shares of South Africa-based financial services group Investec gained 2.2% after it said it expected an up to 114% rise in half-year profits.
Britain’s Mitchells & Butlers Plc rose 1.4% after it said sales over the past two months had been above pre-pandemic levels.