Appointments have previously been made by the panel chairman.
The panel considers complaints under the Portman Group’s alcohol marketing code and current vacancies are for someone with drinks industry experience and a person from an advertising or marketing background.
Sir Richard Tilt, the current panel chairman, said: “The panel performs a vitally important role in ensuring the strict standards for alcohol marketing in the UK are upheld.
“I am seeking applications from people with expertise, objectivity and sound judgment.”
Portman chief executive David Poley said: “While the appointments process has worked very well until now, I believe that advertising the vacancies is in line with the principles of openness and transparency to which we aspire.”
Details on how to apply can be found at www.portmangroup.org.uk.