United Bus was a bus manufacturing group created by DAF Bus and Bova (both from the Netherlands) in 1989. It was later joined by Den Oudsten (Netherlands), Optare (UK), and DAB (Denmark).
The collaboration between DAF and Optare led to the introduction of the DAF DB250 double-decker with Optare Spectra bodywork. This was the first partly low-floor double-decker and set the standard for future developments.
Due to the 1991-1995 world recession, United Bus filed for bankruptcy in 1993, though the partners survived independently.