Christina Norman, former CEO of OWN (OWN/OWN)

OWN network is a joint venture of Winfrey and Silver Spring-based Discovery.

“With the final taping of ‘The Oprah Winfrey Show’ only a few weeks away, I will soon be able to devote my full energies to OWN. This is a natural point of transition,” Winfrey said in Friday’s announcement.

She said she and Ligouri will work together to recruit a permanent CEO.

Discovery Communications, meanwhile, said the change reflects, “a transition from a launch phase to a more long-term focus on business and creative strategy, development and execution following the network’s debut.”

That’s network speak for “network has been struggling, ratings-wise since its launch in January.”

OWN launched last January with strong numbers, but has not continued that momentum. In a recent phone conference call to discuss Discovery Communications’ first-quarter financial results, CEO David Zaslav said OWN’s ratings have been “below” expectations.

“Peter is Discovery’s creative leader, and highly qualified to assume the leadership at OWN for the next phase of growth,” Zaslav said in Friday’s announcement.

“Christina did a great job launching OWN with long-term support from both advertising and affiliate partners. Peter will now ensure that OWN reaches its full creative potential with great programming that delivers on Oprah’s vision, mission and brand,” he added.

Norman has been named CEO at OWN in January of ’09. She came to OWN a 17-year veteran of MTV Networks and; since 2005 she had been president of MTV, in charge of all aspects of the network’s creative and business affairs.

Meanwhile, among his primary responsibilities as Discovery’s COO, Liguori oversees Discovery’s interests in its joint venture channels, The Hub, 3net and OWN. Before joining Discovery in 2009, Liguori had overseen entertainment programming at Fox Broadcasting Company, after serving as CEO of FX Networks, where he was in charge of business and programming for both FX and Fox Movie Channel.