CityJet, the Air France owned Irish airline, is to spend $221m (€174m) on replacing and expanding its fleet.
The airline, which operates five flights a day from Dublin to London City Airport, has bought 23 planes that had been repossessed from a bankrupt US airline. In addition to the Dublin-London route, CityJet operates on a number of other European routes into Paris.
The new planes will be used to replace some of the older BAe146 jets that have served the company for more than 12 years.
Geoffrey O'Byrne-White, CityJet's chief executive said that this was the largest investment in the history of the airline. The first of the new aircraft will be in service by next November and all will be operating by mid-2007.
CityJet is based in Swords, Co Dublin, and employs 580 staff. The airline carried 1.5 million passengers last year, with a turnover of €254m, an increase of 18% on the previous year.
