78-year-old Bajaj, who is survived by his wife, two sons and a daughter, was a member of CPI(M) Central Committee and a founder member of the Centre of Indian Trade Unions (CITU) in 1970 who rose to become its all-India Vice President.
He joined public life through the Revolutionary Communist Party of India and joined CPI(M) in 1964. Bajaj participated in the movement for the liberation of Goa from Portuguese occupation and was arrested. He was imprisoned several times during his five-decade-long political life, the party said here.
In a condolence message, the CPI(M) Politburo expressed deep grief at his death and said the party has lost an outstanding leader of the working class movement in Maharashtra.