COMSA is specialized in the construction, renovation and maintenance of metro lines.

In Spain it has collaborated in the construction of metro lines in Barcelona, Bilbao, Malaga, Madrid and Valencia. Internationally it has participated in projects in Lisbon and Porto (Portugal), Ankara (Turkey), Kuala Lumpur (Malaysia) and New Delhi (India). At the same time, the company has also worked on light railway systems in Barcelona, Madrid, Tenerife and Manila (the Philippines).

see list of works