'I'm not a lesbian' says tearful Oprah Winfrey

The influential TV talk host addressed the nature of her 20-year relationship with Gayle King in an emotional interview with journalist Barbara Walters that will be broadcast on ABC television on Thursday.

"She is the mother I never had. She is the sister everybody would want. She is the friend that everybody deserves. I don't know a better person," Winfrey said of King, fighting back tears.

"It's making me cry because I'm thinking about how much I probably have never told her that. Tissue please," she added.

King and Winfrey, 56, met while working at a local Baltimore TV station in the 1980s and have been inseparable professionally and personally, sparking much media speculation that they are gay.

"I'm not a lesbian. I'm not even kind of a lesbian," Winfrey told Walters, in an excerpt of the interview released on Wednesday. "And the reason why it irritates me is because it means that somebody must think I'm lying. That's number one. Number two...why would you want to hide it? That is not the way I run my life."

Winfrey, whose daily TV chat show is watched by millions in the United States and 145 other countries, also has a more than 20-year, low-profile relationship with businessman Stedman Graham.

Walters said on Wednesday that the couple share a house together and that Winfrey speaks of that relationship in the hour-long interview.

Winfrey is launching a new cable TV network, OWN, in January in a joint venture with Discovery Communications. She will end her ABC TV talk show in May 2011 after 25 years.