"We are living separately and we are much happier this way," the pair tell E! News in a joint statement.
"But we will always have much love and respect for each other. Even though we are separated, we will always remain best friends and, as always, our family will remain our number one priority."
A close family source tells PEOPLE, "There's actually no real drama. Bruce moved to Malibu in June and they liked that arrangement better. They just acknowledged they are separated."
The couple has faced numerous split rumors. A year ago, a source told PEOPLE, "This same basic story has been on covers of mags for the last year and none ... is true."
Their breakup is the latest marital problem in the famous family.
Kris's daughter Khloé Kardashian and Lamar Odom have been struggling with their marriage. And daughter Kim Kardashian recently finalized her divorce from Kris Humphries.
Kris, 57, and Bruce, 63, wed in April 1991, just a month after the matriarch got divorced from Robert Kardashian, O.J. Simpson's former famed attorney.
Bruce, who was previously wed to Linda Thompson and Chrystie Crownover had two children with Kris – daughters Kendall, 17, and Kylie, 16. Bruce also had sons Brandon and Brody from his marriage with Thompson.
Bruce, who has been like a second father to the Kardashian kids after their father died in 2003 of cancer, frequently bickered with his wife on their E! reality show, but the two always maintained a united front.
On Monday, Kris was photographed out with Britney Spears's ex-fiancé Jason Trawick. She was spotted sans wedding ring.
Reporting by JENNIFER GARCIA