Vocento, which owns the conservative daily ABC, will take an undisclosed percentage of Steinberg's annual profits. A spokeswoman for the agency said that Vocento plans to take over 100% in the medium term to incorporate it as a fully-owned subsidiary.
Steinberg will also provide events support to Vocento. Activity will be managed from the agency's Madrid office, under report to Vocento's communications and marketing directors Angel Rojas and Juan Luis Moreno.
According to the spokeswoman, Steinberg will eventually offer other services to Vocento including PR, media relations, sponsorship management and advertising.
Vocento owns several media platforms including 13 newspapers and 42 regional TV stations in Spain.
Owned by Victor Steinberg, Steinberg opened its doors in 1997. Clients include the Nelson Mandela Foundation and Telefonica.