ROBERT J. CALLANDER, 71 years old and a longstanding director of advertising holding company Omnicom Group Inc., quit the board unexpectedly after expressing concerns about the creation of an
entity that houses Omnicom's Internet assets. The entity, now called Seneca, is structured as a private partnership in which Omnicom holds preferred stock that it doesn't control. Callander also has
had some broader corporate-governance concerns.
