KUALA LUMPUR/SINGAPORE (Reuters) - Shares in Malaysia’s AirAsia Group Bhd (AIRA.KL) tumbled more than 17% on Wednesday in their biggest daily fall after the auditor cast doubt on the budget carrier’s ability to continue as a going concern due to the coronavirus travel slump.

AirAsia said in response that Malaysia’s stock exchange had granted it 12 months relief from being classified as a financially distressed firm, a classification that would require it to submit a business improvement plan.

“EY is waving a red flag, which signals to investors and creditors serious risks to AirAsia if the current crisis doesn’t end soon or if the airline doesn’t get a cash injection,” said Shukor Yusof, head of aviation consultancy Endau Analytics.

Shares in AirAsia, one of Asia’s biggest budget carriers, have plunged 58% this year, giving it a market value of about $550 million.

“There’s a question mark over the viability of the low cost carrier business model post-COVID19,” said Yusof, adding AirAsia had little choice but to shrink its fleet size and slash staff and saying its efforts to expand in India and Japan had not been successful.