Rao who was due to superannuate on December 31, 2013, has been granted extension for a period of two years with effect from January 1, 2014, BHEL informed the stock exchanges.
"Department of Heavy Industry, in a communication dated December 31, 2013, has conveyed approval for the extension of tenure of B Prasada Rao, CMD BHEL," the company said in a regulatory filing.
Earlier this week, a panel of secretaries set up by the Prime Minister's Office (PMO) recommended granting a two year post-retirement extension to Rao.
Rao took over as CMD of the company in 2009.
BHEL, shares were trading at Rs 176.10, down 0.20 per cent on the BSE.