Someca (Société de Mécanique de la Seine) was a French tractor manufacturer founded in 1953. The company was as an "Offshoot" of French manufacturer SIMCA (Société Industrielle de Mécanique et Carosserie Automobiles) founded in 1934. SIMCA built vehicles under licence from Fiat who also held shares in the company. The Someca tractor models are also (mainly ?) based on Fiat models.
In 1953, SIMCA bought out the agricultural motors and tractors division of the company MAP, which it then used as the basis for the creation of SOMECA ("Société de MECAnique de la Seine"). SOMECA went on to produce the very first SOMECA tractors and parts for the last tractors to be produced by MAP.
The first Someca model was based on the MAP DR3 design a 37 hp agricultural tractor. SIMCA having taken over MAP who SOMECA had supplied with components. The model DA50 was followed by the SOMECA SOM 40 with a 4 cylinder diesel engine of 4.16 litre capacit and a power of 45 hp @1500 rpm. They built 18,741 between 1957 and 1964. The company built many models with petrol or diesel engines.
By 1960, more than 40,000 SOMECA tractors based on Fiat Trattori were produced.
Beginning in 1965 with the launch of the series 15, SOMECA not manufacture more than Fiat Trattori under license. FIAT has always been the majority shareholder of SOMECA and integrated it in its subsidiary Fiatagri division in 1983, which became Fiat New Holland in 1993 before being Fiat CNH Global now.