In 1929 Vickers Ltd and Cammell Laird merged their rolling stock activities in a new company, the Metropolitan-Cammell Carriage, Wagon and Finance Company Ltd with Vickers and Cammell Laird each holding 50% of the shares of the new company. Following the Second World War, the company manufactured carriages for the railways of the world, including UK, USA, Canada, South Africa, Hong Kong, Singapore, Brazil, Jamaica, and Egypt. In addition, the company manufactured mineral wagons, diesel multiple units and locomotives. However, over this period of sustained high output, international industrial development together with reductions in home market demand as orders were fulfilled, led to the necessity to reduce capacity and in 1962 the Saltley Works were closed and eventually the whole enterprise was concentrated at the Midland Works offices at Leigh Road, Washwood Heath.

In the 1970s Metro-Cammell specialised in the design and construction of rapid transit vehicles for customers such as London Underground, Tyne and Wear Metro, Hong Kong Mass Transit Corporation and the Kowloon Canton Railway Corporation. They also built Maglev vehicles for Birmingham Airport, diesel multiple units for BR and Mk IV coaches for BR. In May 1989 the Laird Group sold their transportation interests to GEC Alsthom and Metro-Cammell became part of the new Anglo-French Power Generation and Transportation Group. This led to involvement in the construction of the Eurostar trains for the Channel Tunnel project. The name Metro Cammell disappeared forever in 1998 when the owners floated the company under the name Alstom.