Government headhunter PESB on Wednesday did not find any of the 12 shortlisted candidates, including serving directors, suitable for the post of NTPC chairman and suggested the government to find incumbent Gurdeep Singh’s successor through the search-cum-selection committee route.This is the latest in a series of instances since 2021 years when the PESB has rejected the panel of candidates interviewed for the top job in ONGC, IOC, HPCL and BPCL. Singh, who himself was selected through this route in 2016, will superannuate on July 31.