Lead-in fares of £69 on new Norwegian transatlantic flights from Edinburgh reportedly sold out within hours.
The budget carrier claimed several hundred fares at £69 were available on each of three new US routes.
They were also offered for new transatlantic links from Cork, Shannon, Dublin and Belfast.
The flights were advertised in other countries at cheaper rates of €69 euros and $65.
The rush for cheap seats led to 20,000 tickets being sold within three days, the BBC reported.
Prices now range from £160 to £280 one-way, with about £65 more to check in one piece of luggage.
A Norwegian airline spokesman said the ultra-low fare was only intended as “an introductory price”, and that affordable tickets were still available.
The Edinburgh routes will connect with small airports in Rhode Island, Connecticut and north of New York City from June 15.