Las Vegas-based National Airlines has closed down after failing to obtain additional funding.
An unnamed backer had pledged to provide extra credit but pulled out and the airline was unable to find any more money.
The airline has been flying under Chapter 11 bankruptcy since December 2000 and until recently had claimed it was confident it would be able to find extra funding.
The airline urged ticket holders to seek refunds from their credit card companies and said some airlines might honour their tickets.
National began flying in 1999 and served 10 cities from Las Vegas.
