Former MindShare investment director Nick Theakstone moves to a new position as chief operating officer of Group M, responsible for non-trading areas, including sponsorship, research and branded content.
Former MediaCom chief executive Allan revealed a string of appointments to Group M, which he claimed had already started leveraging the might of the combined £1.8bn billings of Media- Com, MindShare and Mediaedge: cia, in the ongoing television trading negotiations.
He said: "We're fortunate because we have in Nick someone with huge experience of trading and we want to take advantage of his knowledge of the MindShare and MEC side of the business," said Allan. "But we've recognised an opportunity for him to expand some of the other Group M areas. Mark wants to put the focus of all his attributes into trading."
With a reputation as a tough negotiator, Collins, who was the first TV trading boss to enter into a dispute with the newly merged ITV, will now be armed with Group M's near 30% share of agency billings, in the new TV trading season, which is already underway.
"The purpose of Group M is to power the WPP agencies in trading and to maximise the benefits to our clients of the combined size of our businesses," said Allan.
"We start officially as a separate unit from January next year, but because we are in the midst of a trading season we have already started negotiating as GroupM."
In other Group M appointments, MediaCom group press director Steve Goodman becomes managing director of print trading, with David Kyffin, managing director of MediaCom Direct, appointed managing director of a direct and digital arm.
One of the biggest issues for WPP, despite its enormous bargaining power, is likely to be how to plot its way through the minefield of potential client conflict.
However, Allan stressed that individual WPP media agencies would continue to be the "heart and soul" of WPP's business, retaining control of planning and implementation "strictly within agency walls".
MediaCom has also made new appointments, with press director Claudine Collins promoted to group press director and Darren Barber and Clive Howse becoming joint managing directors of Direct MediaCom.
MediaCom is expected to appoint a new broadcast director in the next few days, with deputy broadcast director David Jowett among those in the frame.