Jose Aldemario Pinheiro Filho, ex-president of the 40-year-old firm, was jailed for 16 years and four months after being found guilty of bribing political officials, money laundering and conspiring to commit crimes.
Fellow former OAS executive Agenor Franklin Medeiros was also served a 16-year term on the same charges.
Three other executives of the conglomerate were given shorter jail terms.
Pinheiro and Medeiros were part of an OAS quartet, including Jose Ricardo Breghirolli and Mateus Coutinho de Sa, to be allowed out on conditional release from jail in late April. They had to wear ankle monitors and were put under house arrest, however.
Operation Car Wash, set up to investigate widespread historical corruption at Petrobras and involving an array of contractors and political figures, has led to the arrest of large amounts of executives and politicians.