The change of tactics from its recent open tender to a closed bid is believed to have been spurred by a change in CEO. Its latest, Than Ching Yee, took over from predecessor Yong Ying-I in late July.
This could set the IDA's selection of a final consultancy back to March 2003.
The search for a successor to Edelman began in October, following the expiry of Edelman's two-year contract covering consumer, business and public affairs work. As a government body, the IDC must open the account up for tender every two years.
Both Edelman and Fleishman-Hillard have presented credentials in a preliminary round of pitching. The IDA would not reveal the identity of other consultancies its brief calls for global capabilities.