NEW YORK – Oprah Winfrey is getting her own TV network.

OWN – for Oprah Winfrey Network – will debut next year in nearly 70 million homes with cable and satellite, part of a deal announced Tuesday with Discovery Communications. It will replace the Discovery Health network.

The announcement builds a media empire that already includes the top-rated TV talk show, a magazine, a satellite radio network, a Web site and TV movies made under her banner.

“This is an evolution of what I’ve been able to do every day,” Winfrey said. “I will now have the opportunity to do this 24 hours a day on a platform that goes on forever.”

She will be chairwoman of the network, owned 50-50 by Discovery and her company, Harpo Productions Inc. In return for taking over a network already operated by Discovery, Winfrey gives half ownership of the Oprah.com Web site.

Discovery owns 13 networks in the United States, including Discovery, TLC and Animal Planet. Discovery Health is one of the least successful, and company President and CEO David Zaslav was looking for ideas about what to do with it when his wife handed him a copy of Oprah’s magazine.

He approached Winfrey about a partnership, coincidentally shortly after she had come upon an entry for her diary dated May 24, 1992, when she wrote about her idea for creating her own network.

“David came and really spoke about the vision I’d been having for 15 years,” she said. “It felt like, ‘I can’t believe you’re saying this.'”

Zaslav said that Discovery’s core mission is knowledge and curiosity and “this is right in our sweet spot.”

Winfrey envisions the programming dealing with issues such as money, health, weight, relationships and raising children. Some of the stable of in-house experts she uses on “Oprah” and the XM satellite radio station might be expected to contribute.

While Winfrey will be the face of the new network, she won’t have much of a presence, at least at first. She is under contract to continue on “Oprah” through May 2011, a deal that prohibits the use of reruns on her own network.

After that, she could continue her show on broadcast TV or do it for the cable network, and may reach a deal to allow reruns on OWN. Taking “Oprah” off broadcast TV, however, could reduce its visibility and in turn make the cable network less valuable.

Winfrey said she needed to decide this fall whether to continue her syndicated show beyond 2011.

Winfrey was an early and visible investor in the development of Oxygen, a network for women that was created in the 1990s. She said she quickly determined that Oxygen “did not reflect my voice” and she removed herself from the company’s board after a few meetings.

“The difference here is I will have editorial control and there is a vision for what I want to do with this network,” she said.

Oxygen was also a startup in an industry where it’s becoming harder to introduce new networks, while OWN will have the built-in advantage of already being in nearly two-thirds of the nation’s homes with television.