Chandrasekaran submitted his resignation on Wednesday, ahead of the Tata Sons annual general meeting scheduled for August 18, the source said. The development comes amid uncertainty over his reappointment to the board of Tata Sons and reported differences between the Tata Sons leadership and Tata Trusts Chairman Noel Tata. Tata Sons, the principal holding company of the Tata Group, oversees more than 30 companies, including Tata Consultancy Services, Tata Motors and Air India. Chandrasekaran joined the Tata Group in 1987 and rose through the ranks at Tata Consultancy Services, becoming its chief executive officer in 2009. He was appointed Tata Sons chairman in 2017, succeeding Ratan Tata.