TN Media will be based in Chicago and have offices in New York and around the world.

A in-house search is under way for an executive to lead TN Media, Mr. Mason said.

That's the analysis of Steve Sternberg, the senior vice president of TN Media, a company that advises advertisers.

Media duties continue to be handled by TN Media in New York, a unit of True North.

TN Media in New York, a unit of True North Communications, continues to handle media duties.

TN Media in New York, a Foote, Cone sibling, continues to handle media buying.

TN Media, part of True North, handles media duties.

Michael Drexler, chairman at TN Media in New York, attributed the departure of the assignment to a disagreement over compensation.

TN Media in Chicago, a sibling True North agency, continues to handle media buying.

"This market has reached critical mass, with buying power greater than ever," said Mike Drexler, chairman at TN Media.