LOS ANGELES - Blair Underwood is joining the cast of the new CTV drama "," playing a visionary billionaire.

The character of Simon Elder will be introduced later in the season as a potential nemesis of the wealthy, troubled Darling family that's the series' focus, which was announced Wednesday. Peter Krause stars as the man hired to protect the family's secrets.

,  and star in "," scheduled to premiere Sept. 26.

The 42-year-old Underwood is also starring in the HBO drama series "In Treatment," set for 2008, and will reprise the character of Mr. Harris opposite Julia Louis-Dreyfus on CBS' "The New Adventures of Old Christine."