CHICAGO—Holding back tears, Oprah Winfrey told her studio audience Friday that she would end her show in 2011 after a quarter-century on the air, saying prayer and careful thought led her to her decision.

Winfrey told the audience that she loved “The Oprah Winfrey Show,” that it had been her life and that she knew when it was time to say goodbye. “Twenty-five years feels right in my bones and feels right in my spirit,” she said.

Winfrey talked about being nervous when the program began in 1986 and thanked audiences who had invited her into their homes and lives over the past two decades.

“I certainly never could have imagined the yellow brick road of blessings that have led me to this moment,” she said.

The powerhouse show became the foundation for her multibillion-dollar media empire but saw its ratings slip 7 percent last season before rebounding in the last couple months. Winfrey, 55, is widely expected to start up a new talk show on OWN: The Oprah Winfrey Network, a much-delayed 50-50 joint venture with Discovery Communications Inc. that is projected to debut in January 2011. OWN is to replace the Discovery Health Channel and will debut in some 80 million homes.