New Delhi, Feb 19 (IANS) Shyam Saran, prime minister Manmohan Singh's special envoy on climate change, Friday announced his decision to quit the job. The decision took many by surprise as Saran was to be elevated to a ministerial rank.

Saran, a former foreign secretary, however, said the decision to quit had been conveyed to the prime minister earlier.

"I had indicated well in advance to the Prime Minister's Office that March 14 would be my last working day. This is not something new. That's all there is to this," Saran told IANS.

"The decision to make him a MoS (minister of state) had been taken because Shivshankar Menon, who is three years junior in service, took charge as the National Security Advisor (NSA)," said an official.

Menon, who retired as foreign secretary in July last year, was appointed the NSA in January.

"Since Saran was a key negotiator in India's climate change diplomacy and enjoyed the prime minister's mandate, (so) the elevation was natural," said the official.

A release from the PMO said, "Shyam Saran, special envoy of the prime minister for Indo-US nuclear issues and for climate change, has been permitted to demit office with effect from March 14."

With India positioning itself as a proactive player in the climate change discourse, Manmohan Singh was keen to assign Saran more responsibilities to carry forward the country's climate diplomacy, said PMO sources.

Saran was instrumental in the drafting of several of the eight missions under India's National Action Plan on Climate Change (NAPCC) to mitigate and adapt to climate change.