Brazilian auto sales rose in May from a year earlier, bolstered by government tax cuts to support the local car industry, sources who have seen preliminary sales data told Reuters.

Sales of new cars, trucks and buses rose 10% year on year to 316,264 vehicles but were down 5% from April though that month had one more working day.

New registrations in the first five months of the year are over eight percent up on January to May 2012 when sagging sales led the government to change the tax regime to favour locally made vehicles.

Fiat continued as top seller of new cars and light trucks in May, according to Reuters sources' data, with 67,850 new registrations in Brazil. General Motors sold 53,829 cars and light trucks ahead of VW's 53,442 sales.

Ford sold 27,546 passenger vehicles last month and Hyundai passed Renault with 19,102 cars and light trucks sold compared to 18,111.