Uk airline Flybe has announced a £3.3bn deal for up to 140 new planes.
The carrier has placed firm orders for 35 Embraer 175 and E-family aircraft, with an option for 65 more, and purchase options on another 40.
The first of the 88-seater planes in the firm order - which is worth around £870m - will be delivered in September 2011, with further deliveries carrying on until March 2017.
Flybe chairman and chief executive Jim French said: "Flybe is delighted to announce this significant order. In doing so, we are securing an aircraft that fits with our stated aim of furthering our position as the leading regional airline in Europe.
"The 175 will allow us to preserve our two-fleet strategy, and the economic and environmental performance of the aircraft is in line with Flybe's policy of only buying A and B-rated eco-label aircraft as part of its commitment to invest in lower-emission, new-technology aircraft."
The planes are made at Embraer's headquarters in Sao Paulo in Brazil.
Flybe, which employs 215 people in Northern Ireland, has been based at Belfast City Airport for over 25 years. It operates 14 direct services from the airport, and the new aircraft will be integrated into the fleet to complement the Q400s and E195 that already fly in and out.
More orders for Airbus aircraft, whose wings are made in the UK, were announced at the Farnborough Airshow yesterday.
Hong Kong Airlines signed a memorandum of understanding (MOU) with Airbus to acquire 15 A350 XWBs and 10 more A330-200s.
Under the terms of the agreement, the airline is converting 15 existing A330 orders to A350 XWBs, and placing an additional order for 10 A330-200s.
Deliveries of the additional A330-200s will begin in 2012, with the first A350 XWB arriving in 2018.
Also, Chilean carrier LAN Airlines signed an MOU for 50 planes from the Airbus A320 family of aircraft, including 10 A321s.
In a separate aviation announcement, British Airways said it was launching twice-daily services from Heathrow to the Swedish city of Gothenburg on November 28.
Stansted bosses announced that the Essex airport had been cleared by the Civil Aviation Authority to take ultra-large aircraft such as the Airbus A380 super-jumbo and the Boeing 747-8.