(Reuters) - Virgin Australia, the carrier owned by Bain Capital, reported a profit of A$236 million ($153.2 million) in the first half of this fiscal year, reflecting a "strong increase" from last year, according to an internal memo seen by Reuters.

The carrier reported interim revenue of A$2.8 billion, citing a robust recovery in travel demand and an increase in profit margins to 8.5% in the six months ended December from 5% a year earlier.

U.S. private equity firm Bain Capital had aimed for a A$1 billion listing of Virgin on the Australian Securities Exchange, but the plans faced delays, Reuters reported last year.

The firm also cautioned of mounting challenges in the market ahead, while its larger rival Qantas posted a nearly 13% decline in first-half profit in February.

"The second half of the financial year will be tough with aggressive market pricing and strong capacity growth and we need to stay focussed on the execution of our plans," CEO Jayne Hrdlicka said in the memo. Hrdlicka had a few weeks ago announced her decision to step down as chief later this year.

Hrdlicka, who also serves as the chairman and board president of Tennis Australia, was the airline's first female CEO. However, she did not provide any further details on when she would depart from the airline.

She is one of the latest executive members to leave the carrier, following the resignation of Chief Development Officer David Marr in October, who had been overseeing the listing plans.

The potential listing would mark the largest new share sale on the Australian exchange in almost two years since GQG Partners raised A$1.18 billion in a 2021 debut.

Hrdlicka also noted that the carrier had made significant efforts to improve its services, "following what were clearly some challenging months in the lead up to Christmas."

($1 = 1.5406 Australian dollars)