Tulchan won the brief from Citigate Dewe Rogerson in 2007, but is not repitching for the account after new comms head Mary Fagan indicated she was looking for a new advisory team.
Fagan, formerly director of corporate and government affairs at the Royal Mail, joined the broadcaster in January, replacing Ruth Settle.
It is thought that the decision to re-tender the account is reflective of the significant board changes at ITV, which in January 2010 saw ITV former Royal Mail boss Adam take over as chief executive.
One industry source noted that Brunswick, having previously built a relationship with Fagan at Royal Mail, was likely to be in a strong position to pitch for the account. Brunswick previously handled ITN's comms, but stopped work with the news organisation earlier this year.
FD and Citigate are likely to be involved, having pitched back in 2007, and could be joined by agencies including M: Communications and Powerscourt.