LOS ANGELES, Jan 22 (Reuters) - Some 28 million viewers worldwide watched Oprah Winfrey's two-part interview last week in which cyclist Lance Armstrong finally admitted he had been taking performance-enhancing substances for years, Winfrey's OWN cable TV channel said on Tuesday. OWN said that 12.2 million Americans and 15 million people overseas watched the encounter over two nights and various airings on OWN, with another 800,000 watching online on Oprah.com.

* Some 3.2 million Americans watch Armstrong's TV confession * Steely Oprah Winfrey gets high marks for effort * OWN hopes interview will translate into more regular viewers By Jill Serjeant LOS ANGELES, Jan 18 (Reuters) - Oprah Winfrey's exclusive TV interview with disgraced cyclist Lance Armstrong drew 3.2 million American viewers - less than the record number who watched the talk show queen interview the family of singer Whitney Houston a month after her death.

* No softball questions from Oprah Winfrey * TV chat show queen shows pulling power with world exclusive By Jill Serjeant LOS ANGELES, Jan 17 (Reuters) - Incredulous, attentive and direct, Oprah Winfrey dug into the psyche of disgraced cyclist Lance Armstrong on Thursday, calling him out as a bully and a brazen liar after he admitted to years of systematic doping.

* Presents opportunity to showcase OWN to new audiences * Success will be determined by ratings, future ad gains * OWN to promote programming to capitalize on large audience By Liana B. Baker Jan 17 (Reuters) - Millions of people are expected to watch Lance Armstrong confess to using performance-enhancing drugs in a two-part interview with Oprah Winfrey beginning this evening, likely giving her OWN cable network its largest audience ever.