Nicky Hilton ends long-term relationship with David Katzenberg

Sources told the New York Post that the breakup was amicable and was the result of their respective work commitments which held them too far away from each other.

“They broke up quietly after four years together,” a friend told the newspaper. “The main reason was that they have been busy with their work schedules, and it has made it difficult to spend time together.”

It’s been four years since the fashionista and her beau, who created MTV’s The Hard Times of RJ Berger, lived a quiet love story, but their working lives have finally taken their toll.

“Nicky has been back and forth traveling overseas a lot with her business,” the source explains. “She has recently been in Asia promoting her jewelry line, and David is starting a new production company. Their schedules never seemed to match.”

However, Hilton, 27, and, Katzenberg, 28, “remain close friends. They have been friends since they were teenagers,” an insider adds.

Nicky’s split from Katzenberg comes shortly after her sister Paris confirmed her separation from Cy Waits.