Officine Specializzate Costruzioni Automobili Fratelli Maserati, or OSCA, was the brand of racing sports cars developed by the Maserati brothers after they had sold out their share of the Maserati concern in the late 1930s to two wealthy industrialists from Modena, Adolfo Orsi and his son Omer. There was a 10 year gap between events, partly because of the war, but mainly because the brothers Maserati were retained on a 10-year contract and supervised the design and development of new models.
In the early post-war years Maserati once more became one of the most prolific racing car manufacturers. In 1947 their contract to the Orsis expired, Bino, Ettore and Ernesto Maserati left Modena to return to Bologna where, with the minimum of capital, they established a new company in a portion of their old, pre-1937 factory. It was known as OSCA (Officine Specializzate Costruzioni Automobili Fratelli Maserati); the brothers had been forbidden to use their own name by the Orsis.
Also see: The History of OSCA