The shares of Norwegian Air plunged by more than 60pc on Tuesday as they resumed trade after the airline proposed a financial rescue package on April 8 that would significantly dilute existing equity.
If approved by creditors and shareholders, the plan would convert $4.3bn of debt into equity, and also raise some new equity, wiping out much of the remaining value of the company's current shares.
The budget carrier has grounded most of its fleet due to the impact of the Covid-19 outbreak on travel and on March 16 announced the temporary layoff of 7,300 staff, about 90pc of its workforce.
Norwegian's shares plunged 62.5pc in early trade to an all-time low of 3.10 crowns, valuing the company at just 500m Norwegian crowns (€44.6m).
Norwegian was facing financial problems even before the coronavirus outbreak.
Before Tuesday's fall, its shares were down 78pc this year, underperforming other major European airlines, which were down between 30pc and 60pc.
The airline must now convince its creditors to agree to the rescue plan before it is put to a shareholders' vote on May 4.
The Oslo stock exchange said on Tuesday that trading in Norwegian's shares would be subject to special observation until there was further clarification of the airline's situation.
Special observation is used under circumstances that may make the valuation of a security particularly uncertain, according to the market operator's guidelines.