On the eve of taking office as the eighth United Nations Secretary-General, Mr Ban yesterday named Mr Nambiar as chef de cabinet and a Haitian journalist as spokesperson.
A UN statement said Mr Nambiar brings years of experience in diplomacy--both within and outside the UN--to the job.
Most recently, he served as Special Advisor to Mr Annan who completed his term yesterday.
''I have known Mr Nambiar for a long time and we share deep confidence and respect for each other...Today's appointments will serve as a solid basis for establishing my team and pursuing a programme of reform of the Secretariat to provide continuity along with change,'' Mr. Ban said.
Mr Nambiar undertook a number of sensitive assignments during his tenure with Mr. Annan, including travelling to West Asia following the war between Israel and Hizbollah.
Before joining Mr Annan's team in March, Mr. Nambiar was India's Deputy National Security Advisor and Head of the National Security Council Secretariat.
He previously served as India's Permanent Representative to the UN in New York, from May 2002 to June 2004.
Earlier as Ambassador of India, he served successively in Pakistan (2000-2001), China (1996-2000), Malaysia (1993-1996) and Afghanistan (1990-1992). He was also India's Ambassador to Algeria from 1985 to 1988.
During his professional career in the Indian Foreign Service, the 63-year old diplomat served in numerous bilateral and multi-lateral appointments in Beijing, Belgrade and New York during the 1970s and 1980s.
Mr Nambiar joined early years in the diplomatic service specialising in the Chinese language serving in Hong Kong and Beijing. He also served during the mid-1970s in Belgrade, Yugoslavia.