Oprah Winfrey is expanding her media empire, laying the groundwork for her own TV network.

Winfrey and Discovery Communications announced plans this week to launch the Oprah Winfrey Network--OWN--in the second half of 2009 on the Discovery Health Channel.

The venture will be half owned by Discovery Communications and half by Winfrey's production company, Harpo Inc. Winfrey will serve as chairwoman and will have editorial control.

The new channel will not initially carry The Oprah Winfrey Show.  But Winfrey said she could choose to end that show in 2010 or 2011 and move it to the new network.

"This is an evolution of what I've been able to do every day," Winfrey told reporters in a conference call Tuesday. "I will now have the opportunity to do that 24 hours a day on a platform that goes on forever."

In addition to continuing her syndicated talk show, Winfrey said she would continue to produce programming for other outlets. A new reality show, Oprah’s Big Give, is scheduled to begin on ABC in March.--Eve Gumpel