Ballymena-based Wrightbus has announced its largest ever order of £125m - to manufacture vehicles for FirstGroup, Britain's largest bus operator.
The contract, which was welcomed by First Minister and local MP Ian Paisley, will keep the company busy for between three and five years.
Wrightbus, which currently has a workforce of 1,000, said today it would provide a platform for further growth.
Wrightbus group managing director Mark Nodder said: "This order shows FirstGroup's commitment to investing in programmes geared to encouraging the public to switch from cars to public transport, which will reduce both congestion and damage to the environment.
"We are pleased to be FirstGroup's partner of choice and this is an excellent endorsement of Wrightbus as a designer and manufacturer of a range of vehicles that incorporate innovative and advanced technology for both drivers and passengers.
"This significant order is the biggest annual investment that the FirstGroup's coach and bus fleet has ever placed.
"Although the bulk of the order will be built on Volvo chassis, it also includes nine new Wrightbus double-decker buses, five of which are hybrids."
FirstGroup chief executive Moir Lockhead said: "Wrightbus was the obvious choice for this substantial investment.
"We have worked closely together for many years and I am always impressed by Wrightbus' innovation and creativity."
Wrightbus said it had faced significant competition from a number of manufacturers throughout the world in its efforts to bag the order.
FirstGroup describes itself as the world's leading transport company with revenues of more than £5bn a year.
It employs more than 135,000 staff throughout the UK and North American and transports more than 2.5 billion passengers a year.
In the UK, FirstGroup is responsible for more than a fifth of all local bus services.
Wright Group, which was founded in 1946, is still a family owned and managed company.