Rajan, who is currently the Additional Chief Secretary in the Panchayat Raj and Rural Development Department, was selected from a panel of three officers by the EC last night, an official spokesman said today.
The other two IAS officers in the panel were B B Mohanty and Umrao Salodia.
Rajan will hold the additional charge which went vacant after Chief Secretary C K Mathew proceeded on a two-month leave following allegations levelled by opposition BJP.
The party had also alleged "gross violation" of the Model Code of Conduct, saying the state machinery was being misused to popularise government's schemes by the Chief Secretary.
On October 18, the state government had sanctioned the leave application of Mathew who proceeded on leave till completion of the election process.
On the directions of the EC, the state government had to submit a panel of three IAS officers for the charge.
