You’ve read all of your free items this month. To register, get added benefits and unlimited access to articles, Become a Member. Already a Member? Sign in. Advertising Age Article Abstract Omnicom's Wren: Coordination Across Agencies 'More Important than Ever' On Earnings Call, CEO Stresses Need to Pool Resources to Serve Big Clients By Rupal Parekh, Published on October 16, 2012 0 Want more Access, Content & Connections? Upgrade to Membership. We are glad you are enjoying Advertising Age. To get uninterrupted access and additional benefits, become a member today. Register Now Already a member? Log in.