County Antrim bus builders Wrightbus have announced a major new order from the UK for 334 new buses.
The contract with bus operator Arriva is valued at around £55m and consists of 204 double-deck and 130 single-deck buses.
Wrightbus managing director Mark Nodder said he was "delighted" at the news.
Arriva runs several routes in cities across the UK including, London and Glasgow.
"This is the biggest order we have secured in several years," Mr Nodder added.
"And it is likely to be the biggest I think in the next 12 months as well.
"We have been thinking for some time that the second half of 2011 was likely to be an improvement on the last 18 months or so, and that seems to be the way it is turning out."
The order also includes the first Wrightbus StreetLite midi-buses to be delivered to an international public transport operator.
Mr Nodder said that the order from Arriva represented six months' work which would take the company up to the end of December.
The 334 new vehicles are due to be delivered between June and December 2011.
Last year, the Ballymena-based company, secured a contract to design London's new "routemaster" bus.
The red double-decker, which uses green technology and has two staircases, is due to be completed in 2012.
London Mayor Boris Johnson described the design as "iconic" and "beautiful".