In 1954 the first commercial relations between Rieder and Siemens began. From there and over the years, representation contracts are signed for the commercialization of products manufactured by Siemens Halske (Communications), Siemens Schuckert Werke (Energy), Siemens Elektrogeräte (Household appliances).

After the unification of the factories under Siemens AG, a contract was signed in 1993 in which Rieder & Cia has the exclusive right to sell Siemens products in Paraguay. Even with the regionalization of Siemens Mundial in 1997, Rieder & Cia continues as the exclusive representative of Siemens AG in Paraguay.

In 2006 Siemens separated its businesses from the telecommunications sector, consequently, Rieder & Cia stopped marketing Siemens public telecommunications products in Paraguay after 50 years, continuing as the exclusive representative in all its products, except medical equipment.

Since 2009 Rieder & Cia has the exclusive representation with Siemens for products, systems and services of the Energy, Mobility, Digital Factory and Process in Industries Divisions and also for products, systems and services of the Power and Gas and Power Generation Services Divisions .

In 2019 Rieder & Cia and Siemens AG signed a franchise agreement for the manufacture of high-tech industrial electrical panels in Paraguay, with certification and registered trademark by Siemens. To date and with more than 60 years of starting relationships, Rieder & Cia and Siemens continue to make history in Paraguay.