The order is the lion's share of a £70m investment in 425 vehicles for the UK bus division of the group.Wrightbus will provide 301 StreetLite buses - 274 of which are specified with innovative "Micro Hybrid" technology - developed exclusively by the Ballymena based-company. The technology captures the energy generated from a bus's braking system, and redistributes this energy to power pneumatics, hydraulic and electrical systems which would otherwise require power from the engine. The result is a reduction in fuel consumption of up to 10%, leading to substantial savings over a bus's typical 15-year operational service life.The company was selected following extensive testing and fuel consumption trials last year.Commenting on the announcement, Managing Director of First UK Bus, Giles Fearnley said: "Our groundbreaking partnership with Wrightbus will deliver unsurpassed levels of fuel efficiency. In 2013 we laid down the gauntlet to bus manufacturers to work with us to minimise fuel consumption. "Wrightbus embraced that challenge and together we've developed its StreetLite Micro Hybrid product. I am immensely proud of our collective achievements and we're very much looking forward to being the first operator to take delivery of these revolutionary new vehicles."The chassis for the new buses will be built at Wrights Group subsidiary EN-Drive in Antrim, with the bodywork to be assembled in Ballymena. Vehicle deliveries will commence during the next few months, with all buses expected to be in full operational service by early next year."This is further great news for Wrightbus and the Northern Ireland economy" said Group Managing Director Mark Nodder. "Hot on the heels of last year's order to build 600 innovative double deck buses for Transport for London, this order for FirstGroup will help secure existing jobs right across our business. "It is a huge endorsement for our innovative StreetLite single deck bus concept and the exciting Micro Hybrid technology that we have developed in conjunction with First."Welcoming the announcement, Enterprise Trade and Investment Minister Arlene Foster said: "This latest order from FirstGroup is yet another vote of confidence in Wrightbus, which has once again proven it is a world leader when it comes to innovation.""Today's announcement underlines the value of the continuing partnership between FirstGroup and Wrightbus. Not only has it secured jobs, it has provided a significant shop window for the Ballymena firm's innovative StreetLite concept and the ground-breaking Micro Hybrid technology behind it."