Under Murthy's 19-year tenure as CEO until 2002, Infosys became the first Indian company to list on Nasdaq and grew to become an over 40,000 crore (USD 7.3 billion) enterprise. He is returning at a time when Infosys has performed below market expectations and has struggled to retain clients in North America and Europe. The firm has over past two years losts its IT bellwether status to Tata Consultancy Services, the country's largest software services exporter.

In FY13, revenues lagged its own forecast and projected lower growth in earnings than industry during the current year.

Infy raises retirement age of executive chairman

Murthy, the poster boy of Indian IT success, said his son Rohan will not have any leadership role and he was there only to make Murthy more 'effective'.

"Standing here today is very unusual to me. When I walked out of Infosys on August 20, 2011, I did not in my wildest dreams imagined that I will be back here in my executive capacity," he told a hurriedly called press conference.

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