Kepcher, a co-star with Trump from the start of "The Apprentice" in 2004 and a longtime employee of the Trump Organization, has been let go.
"Mr. Trump wishes her the best," said Trump spokesman Jim Dowd, who confirmed she is no longer with the company. She had been chief operating officer of two of Trump's golf courses.
"Donald and I had different visions for my future role in the company," Kepcher said in a statement. "Donald has been an extraordinary boss and a great mentor over the years, and I will always be grateful."
Her leave-taking will have no impact on the upcoming sixth season of "The Apprentice," originating for the first time from Los Angeles, NBC said. Though production is completed, Kepcher was not part of the cast, which includes Trump children Ivanka and Donald Jr. It begins airing in January.
Kepcher's dismissal was first reported in Thursday's New York Post.
The slender, striking blonde had become familiar to viewers as one of Trump's two sidekicks on the NBC series. She was an adviser to one of the rival teams and was often seated beside Trump for boardroom sessions where one or more competitors would hear Trump declare, "You're fired."
The Post attributed Kepcher's firing to excessive self-promotion as a star at the expense of her performance at her day job, an account echoed for The Associated Press by a person close to the situation. The person insisted on anonymity because it was a personnel matter.
Kepcher could not be immediately located for comment.
Since TV fame beckoned, Kepcher has been active with speaking engagements, made a number of talk-show appearances and two years ago wrote a book, "Carolyn 101," which promised to reveal the secrets of her success and give readers guidance for their professional lives.