Sikri, 62, a former Gujarat cadre IAS officer, will become the third chairman of the fair trade regulator. He will succeed Ashok Chawla, who superannuated on January 7.
Chawla, a former Finance Secretary, had taken over as the Chairman from Dhanendra Kumar who demitted office in June 2011.
"Devender Kumar Sikri to take oath as Chairman of the Competition Commission of India today in New Delhi," the Finance Ministry said in a tweet.
He will be at the helm of CCI, which keeps a tab on unfair business practices in the market place across sectors, till attaining the age of 65 years.
A seasoned bureaucrat, Sikri had held various positions at the Centre as well as in his cadre state of Gujarat.
He superannuated as Department of Justice Secretary in July 2013. Sikri takes over at a time when the regulator is working on ways to strengthen its human resource, create more awareness about competition norms and enhance vigil on emerging sectors to curb possible anti-competitive business practices.
Apart from the Chairman, CCI has six members.