County Antrim-based Wrightbus has won a contract to supply Transport for London (TfL) with 200 new Routemaster buses.
The new order will secure jobs at the company's Ballymena and Antrim plants, the company stated. The buses are to be delivered by June 2016.
Wrightbus chair Mark Nodder said: "The order will secure jobs in Ballymena and Antrim, underpin our programme of continuous innovation and benefit our local supply base in Northern Ireland."
According to Leon Daniels of TfL, the new vehicles will cut vehicle noise and emissions while improving passengers' journey experiences.
Wrightbus was awarded the contract to build the new hybrid Routemaster bus in 2010 and the so-called 'Boris bus' entered service in 2012. Some 600 of the vehicles have already been ordered.
The company employs almost 2,000 people and exports to international markets, including Singapore and Hong Kong.