All of the airline’s trips between major-city airports have been cancelled as the financially struggling carrier looks for investors or a buyer to continue its regional operations.

Rex’s regional flights continue to run, while rival airline Virgin Australia has chipped in to help customers booked on capital-city routes onto alternate flights.

Administrators EY on Wednesday said they were confident the airline’s status as a key regional carrier would continue, while also indicating Virgin had expressed an interest in taking on a number of Rex’s grounded Boeing 737s from axed major routes.

Virgin said 4600 Rex customers had been in contact about alternate bookings by early Wednesday morning and 500 had already been placed onto new flights.

Impacted customers with tickets on cancelled Rex flights can transfer free of charge to Virgin services.

Rex employed about 2000 people, with almost a third expected to lose their jobs, the Transport Workers Union said, citing estimates from administrators.

“This is another dark day for aviation, with over 600 families faced with sudden joblessness in an industry that has taken hit after hit,” TWU national secretary Michael Kaine said.

“The focus now must be on maximising jobs, protecting regional routes, securing redeployment opportunities to other aviation businesses and ensuring entitlements are paid as soon as possible.”

The Rex board has appointed Samuel Freeman, Justin Walsh and Adam Nikitins of EY Australia as joint administrators.

Mr Freeman forecast a “relatively short” administration period before new investment took the business forward.

“There has been a groundswell of support for the Rex business since our appointment … there’s a great prospect there is a future for Rex, and it’s a strong likelihood it will be delivering services to the people of regional Australia,” he told ABC Radio.

Rex and Virgin Australia are exploring ways to support regional customers, including Virgin selling Rex’s regional services through codeshare or interline arrangements, and making Virgin frequent-flyer benefits available.

Mr Freeman said state and federal governments had been in contact since the administration began, but would not indicate if financial support had been discussed.

The TWU has called for the federal government to buy an equity stake in Rex to minimise job losses and protect regional Australia.

Treasurer Jim Chalmers said it was a “big relief” Rex would keep servicing regional areas while in administration, adding that a federal support package had been discussed.

“Obviously, there’s been discussions but … we want to hear next from the company,” he told ABC TV.

“Our top priority (is) to make sure we can continue to serve and service regional communities and regional economies because we know how important it is – we’re prepared to play a constructive role.”

Many regional communities rely on the carrier, which emerged 22 years ago following the collapse of Ansett.

Unlike Bonza, which went into voluntary administration in April, Rex mainly owns rather than leases its planes.

Rex’s key fleet comprises 61 SAAB 340s and seven leased Boeing 737-800s, out of 123 aircraft in total.

Rex shares were suspended from trade on Wednesday after earlier being placed in a trading halt amid speculation that administrators would be called in.

It has struggled with profitability since aggressively expanding to compete on capital-city routes with the dominant domestic operators, Qantas and Virgin, after the pandemic.

In February, it reported a net loss of $3.2 million for the first half of the 2023/24 financial year.