Ferrocarriles Metropolitanos S.A. (FEMESA) was a company set up by the Argentine government in 1991, during the presidency of Carlos Menem, to oversee the privatisation of commuter rail services within the city of Buenos Aires in Argentina. The company granted concessions to Metropolitano S.A., Ferrovias S.A., Metrovias S.A. and Trenes de Buenos Aires S.A. for the operation of services which had previously been run by state-owned companies since nationalisation of the railways in 1948.