Royal Dutch Shell's chief executive Ben van Beurden has noted the oil and gas giant plans to invest billions of dollars off Shetland in coming years, signalling the company has no major concerns about the prospect of Scottish independence.

Asked if Shell was making contingency plans for how to respond to a vote in favour of independence in September, Mr van Beurden said:

"As I've said before in December I think we would prefer it for the UK to remain a single country. There is of course uncertainty that would flow from a Scottish independence outcome but then having said that we would of course deal with Scottish independence in the way that we would have to. I don't think there is in that sense anything that we are deeply concerned about."

Mr van Beurden, who took charge in January, said the North Sea still had a big part to play in the company's plans although he intends to sell off billions of dollars of assets around the world.

While Shell has put three relatively small assets off Scotland up for sale, Mr van Beurden noted: "You have to bear in mind that there's also significant growth still. We still invest for the next few years two billion dollars a year particularly in Clair and Schiehallion (West of Shetland) so it's not as if we are completely stepping away from the North Sea. We are just engaged in the normal active portfolio management where we prune ourselves of end of life, late life assets and where ownership is better had elsewhere because there is niche or specialist capability ... and where basically we have bigger bang for our buck elsewhere. "

The Dutch executive was speaking to reporters after Shell posted a 33 per cent increase in quarterly earnings, helped by high oil prices.

The company made $6.1 billion (£3.6bn) net of one-offs in the three months to June, compared with $4.6bn in the same period of 2013.

Mr van Beurden spoke of his sadness about the crash of the MH17 Malaysia Airlines flight in east Ukraine earlier this month, which took the lives of four Shell employees and many of his compatriots and which he described as a terrible tragedy.