The airline said the money would be "used exclusively to support the launch and operation" of its new Boeing 737 services between Australia's capital cities.

"This is the final major step in REX's preparation for launching domestic services to all the major cities," Rex deputy chairman John Sharp said.

"It's a historic moment for REX and for Australian aviation, providing Australians for the first time a premium reliable service at affordable fares."

REX was formed in 2002 via a merger of Wagga-based Kendell Airlines with Hazelton Airlines in the Central West, with the airline running a pilot academy at Wagga's airport.

As a result of a motion carried at the Regional Express (REX) annual general meeting on Friday, Singapore-based PAGAC Regulus Holding was granted a 23.3 per cent shareholding in exchange for $50 million.

PAG Regulus Holding is a subsidiary of PAG, formerly known as Pacific Alliance Group, a Hong Kong-based private firm that says it manages $65 billion of investments across Asia.

PAG will increase its REX shareholding to 47.6 per cent over the next three years if it provides another two payments of $50 million.

REX first announced plans for a new domestic jet service in May at the height of the coronavirus pandemic that had severely disrupted the airline industry and caused REX to seek tens of millions of dollars in federal government bailouts.

Mr Sharp said REX had already leased six Boeing 737-800NG aircraft, painted them in the airline's livery and "recruited highly qualified pilots and cabin crew".

"I'd like to thank all of those involved in getting to this stage. It's been a challenging year in aviation, and to achieve what Rex has achieved is remarkable," Mr Sharp said.

REX is due to receive the first $50 million from PAG within two weeks and aims to launch its new jet service on March 1 with $79 introductory fares between Sydney and Melbourne.

The airline has previously said it will offer "seamless" connections between its existing prop-driven services out of Wagga and its new capital city services.

Under the deal, PAG will be able to nominate for two positions on REX's board and one seat for its newly created subsidiary, Rex Airlines, which will run the domestic jet service.