New Delhi, Aug. 12 -- Tata Sons chair N. Chandrasekaran has resigned, seven months before the end of his second five-year term that was to end in February next year, throwing the country's largest conglomerate into uncertainty.

He said in a letter to the board of Tata Sons on Wednesday morning that he will not seek reappointment after completing his current term on 20 February 2027, according to an executive privy to the development.

Chandrasekaran, 63, was appointed as the chair of Tata Sons, the principal investment holding company of the $400-billion Tata Group, in February 2017 and given a second five-year term in 2022.

In his letter, Chandrasekaran, who has completed 40 years of his professional life at Tata Group, said Sir Dorabj...