Within a year of J Suresh Kumar quitting as Lanco Infratech’s chief financial officer, another senior executive in the company, Philip Chacko, has quit as head for investors’ relations. Lanco Infratech has accepted his resignation and he has been replaced by Dheeraj Sud, a former investment banker. Chacko is expected to join the Vedanta group. Chacko was associated with Lanco for about four years.