Tom Cavanagh, Eric McCormack star in series

TNT has greenlit the Tom Cavanagh-Eric McCormack series "Truth in Advertising" for next season, giving the cable channel three new shows for 2008-09.

"Truth in Advertising," which is set at a Chicago ad agency, is scheduled to premiere in 2009. It centers on Mason (McCormack, "Will & Grace") and Conner (Cavanagh, "Ed"), creative executives at the firm and long-time friends whose relationship changes when Mason earns a promotion. It will also delve into the firm's internal politics as it prepares for a public stock offering.

The show also stars Monica Potter ("Boston Legal"), Sarah Clarke ("24"), Griffin Dunne ("The Great Buck Howard"), Mike Damus ("Men, Women & Dogs") and Geoffrey Arend ("The Ringer," "Daria"). Hunt Baldwin and John Coveny, writers for TNT's hit "The Closer," penned the pilot and will executive produce with Greer Shepherd and Michael M. Robin, also of "The Closer." Robin directed the pilot.

"We are thrilled to be working on this superb drama with the creative talents who brought us 'The Closer,'" TNT's Michael Wright says. "And we are especially happy to have such a stellar cast, led by Eric and Tom."

"Truth in Advertising" joins the Steven Bochco legal drama "Raising the Bar" and the Dean Devlin series "Leverage" on TNT's roster for next season. The network has also amped up its development, with the goal of having three full nights of original programming by 2010.

McCormack won an Emmy, and was nominated three more times, for playing Will on NBC's "Will & Grace." He'll next be seen in A&E's remake of "The Andromeda Strain," which premieres next month.

Cavanagh, whose credits also include "Love Monkey" and "Scrubs," currently has a recurring part on ABC's "Eli Stone." He also stars in Lifetime Movie Network's "The Search for the Green River Killer," which debuted to solid ratings over the weekend.