Sihag, who also holds the charge of Financial Adviser in the ministry, will remain at the helm of affairs at the National Mineral Development Corporation for three months or till a regular incumbent is appointed, whichever is earlier.
NMDC in a BSE filing said: "In terms of order dated January 11, 2016 of Ministry of Steel, the additional charge of the post of CMD NMDC is assigned to Bharathi S Sihag, Additional Secretary and Financial Adviser, Steel Ministry."
The previous CMD of the country's largest iron ore miner Narendra Kothari retired on December 31.
Government's head hunter Public Enterprises Selection Board (PSEB) recommended Gopal Singh for the top post, but sources said that Appointments Committee of the Cabinet has still not given its nod on the same.
Gopal Singh has been heading Central Coalfields Ltd (CCL) since March 2012.