The Appointments Committee of the Cabinet (ACC) has approved the curtailment of tenure of Mittal, an order issued by the Department of Personnel and Training (DoPT) said.
Mittal, a 2011 batch IAS officer of union territories cadre, was in August 2016 appointed as the PS to the minister for a five-year term.
According to another order, Amitabh Prasad has been appointed as PS to Railways Minister Piyush Goyal.
The ACC has approved appointment of Prasad as PS to the railways minister in addition to his duties as Officer on Special Duty (OSD) to the Minister of Coal, it said. Goyal is also the Coal Minister.