Virgin Atlantic will report a loss when it publishes its 2018 accounts this week, but at a reduced level from the previous year.

Chief executive Shai Weiss expects the carrier to break even next year and be back in profit by 2021, provided there is an orderly Brexit.

The airline lost more than £28 million in 2017, the most recent year for which results are available.

However, he believes Virgin Atlantic’s new partnership with Air France/KLM will help it return to the black because it will link it into the kind of worldwide alliance any airline now needs to succeed as passengers demand seamless connectivity to almost any destination.

The Franco-Dutch airline partnership paid £220 million for a 31% stake in Virgin Atlantic last year.

When the deal is completed this summer, frequent flyers on Virgin Atlantic and 49% shareholder Delta Air Lines will be able to book seats and earn loyalty points and air miles on flights to the 340 destinations served by the alliance. Air France and KLM frequent-flyers will be able to travel to London and on to the US with Virgin or Delta, or both, on a single booking.

“Business customers now see us as a great alternative to BA/American Airlines,” Weiss said.

Weiss, promoted to the top job in January, was speaking to The Sunday Times as the airline prepares to unveil new cabins as part of a £3 billion order for 12 Airbus A350s.

The new aircraft, due to enter service in late summer, will mark a return to growth after a period on contraction with new routes to Tel Aviv and Sao Paulo from Heathrow and more frequency on other transatlantic routes. A return to Tokyo and Mumbai is under discussion as well as a route to Bejing.

The recent acquisition of loss-making Flybe by a Virgin-led consortium will feed more passengers into Virgin’s long-haul hubs.

Virgin Atlantic and its partners are investing £100 million “to take Flybe to the next level as we rebrand it”, Weiss told the newspaper.

The takeover deal is expected to be approved by regulators this summer.

Weiss insisted Flybe will be profitable because it has the scale that Virgin’s short-lived short haul venture Little Red lacked.

“Flybe has 8.5 million passengers. It operates at 79%-to-even-higher load factors. It has an established network with 12 slots at Heathrow and hundreds in Manchester,” he said.

A decision has not yet been made on the name for the rebranded regional carrier but it will carry the Virgin name.

More: EU approval granted for control of Virgin Atlantic