Shell posted second-quarter profit of $4.26 billion, beating analyst expectations, and said it would buy back $3.5 billion of shares over the coming three months. The results come shortly after the London-listed firm flagged weaker trading results at its integrated gas division.

Shell's second-quarter net profit tumbled by almost a third on Thursday, dragged down by a drop in oil prices, lower gas trading results and outage-related losses from its chemicals operations, but it still easily beat analysts' forecasts.