Rangarajan, 77, who will replace Suresh Tendulkar, gave his resignation to Rajya Sabha chairman Hamid Ansari, who has accepted it.
"I have resigned my Rajya Sabha seat and will be taking over as the chairman of the PMEAC from tomorrow", Rangarajan told PTI.
A former Reserve Bank Governor, Rangarajan is a close confidant of Prime Minister Manmohan Singh and had headed the PMEAC for three years from 2005. In 2008, he was nominated to the Upper House.
The appointment comes at a time when the government is faced with challenges of economic recovery from the effects of global meltdown and a looming drought at home.
Image: C Rangarajan