Rao will help enhance and strengthen the group's engagement with the Asean region, a statement from the company said.
Since the early 1970s, the Tatas have presence in the city-state.
They began with setting up a precision engineering company and training centre, on Thursday, over 15 Tata companies are present in the city in diverse areas, including manufacturing, engineering, communications and IT, chemicals, energy, and financial services, employing over 3,100 people and with investments/assets over $7 billion.
The Tatas are present in over 100 countries and export products and services to 150 countries.
Of the $96.79 billion revenue last fiscal, 62.7 per cent came from overseas.
A resident of Singapore for the past 18 years, Rao has served in the Singapore Civil Service and will continue to serve as managing director of Trust Energy Resources, a Tata Power subsidiary.
Image: Bombay House, Tata Sons' head office; Photograph: Rediff Archives
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