United Bus was a bus

Bus

A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...

 manufacturing group created by DAF Bus and BOVA (both from the Netherlands) in 1989. It was later joined by Den Oudsten

Den Oudsten

Den Oudsten Bussen B.V. was a Dutch coachbuilder and components manufacturer. The company was founded in 1926 by a local carriage-builder, Marinus den Oudsten. The company's headquarters were based just outside the city of Woerden...

 (Netherlands), Optare

Optare

Optare plc is a bus manufacturer and importer based in Leeds and Blackburn, UK. The company operates from three main business units, Bus Manufacturing, Coach Sales and Unitec....

 (UK), and DAB (Denmark).

Collaborations

The collaboration between DAF and Optare led to the introduction of the DAF DB250 double-decker with Optare Spectra

Optare Spectra

Launched in 1991, the Optare Spectra is a double-decker bus body built on the DAF DB250 chassis.The vehicle was developed as a joint project between Optare and DAF; based on the designs of the successful MCW Metrobus which Optare had purchased, but they are no means a restlyed Metrobus...

bodywork. This was the first partly low-floor double-decker and set the standard for future developments.