A delay to Britain's EU departure and the possibility of it leaving without a deal in October has kept Brexit centre stage at the Paris Airshow, where East said it had dominated a meeting with heads of aerospace companies and a European commissioner.

"It's nuts that at a meeting like we had this morning, when we were meant to be talking about new technologies, dealing with global competition, that instead we spend half the time talking about Brexit. It's hugely disruptive," East told Reuters.

Britain voted to leave the EU in June 2016 but has failed to do so, with Prime Minister Theresa May resigning after repeatedly failing to pass a Brexit deal. Some leading candidates to replace May suggest the deal can be reopened, although the EU insists it is not open for renegotiation.

Brexit has been delayed until October 31 from March 29, and East said Rolls-Royce had spent money on contingency plans for a March departure that it will not get back.

The prospect of a "no-deal" Brexit is a headache for the global aerospace industry, which relies heavily on integrated supply chains and parts distribution centres.

East said that he was prepared for the possibility, but was unlikely to make specific plans for the October deadline in the same way as he had done for March.

"I'm not sure we're going to spend as much preparing for some deadline that might never happen. It's just an unnecessary distraction for businesses," he said.

East, who took over as CEO of Rolls-Royce in 2015 after previously running chip designer ARM, has been leading a transformation programme which he said was on schedule.

"Everything I can see at the moment suggests that we're going to tell the market that we're absolutely on track," East said ahead of half-year results due on Aug 6.

(Reporting by Alistair Smout; Editing by Alexander Smith)

By Alistair Smout

Stocks treated in this article : Euro / British Pound (EUR/GBP), Rolls-Royce