Lauda won two of his titles with Ferrari before claiming his third with McLaren after coming out of retirement. 
 

Ferrari
Today is a sad day for F1. The great Ferrari family learns with deep sadness the news of the death of our friend Niki Lauda, three times world champion, two with the Scuderia (1975-1977). You will remain forever in our hearts and in those of the fans ...Keep reading

Source: Motorsport fraternity pays tribute to Lauda