The 72-year- old Jat leader has been allocated the Civil Aviation Ministry portfolio on the advice of the Prime Minister Manmohan Singh.
Meanwhile, with the RLD joining the ruling party, the UPA’s strength in the Lok Sabha went up from 272 to 277 members.
The move is in the wake of seat-sharing agreement between the Rashtriya Lok Dal and Congress for the forthcoming Uttar Pradesh elections which is likely to be held in Feb 2012, where RLD would be contesting in 45 out of the 403 seats.
It is learnt that Congress made the agreement with Ajit Singh to affirm its victory in western UP, where Ajit Singh's party has a sizeable vote bank among the Jats, Muslim and upper caste votes.
Ajit Singh has become the 33rd minister in the Union Cabinet and 77th in the Council of Ministers. This is the fourth time Mr Singh has been inducted into the Union Cabinet.