New York: Heiress Paris Hilton`s sister Nicky has reportedly split from longterm boyfriend David Katzenberg.
The pair were together for four years and busy work schedules forced them to part ways, reported a newspaper.
"They broke up quietly after four years together. The main reason was that they have been busy with their work schedules, and it has made it difficult to spend time together," said a source.
"Nicky has been back and forth travelling overseas a lot with her business. She has recently been in Asia promoting her jewelry line, and David is starting a new production
company. Their schedules never seemed to match."
The insider added Nicky, 27, and, Katzenberg, 28, "remain close friends. They have been friends since they were teenagers."
Since her split with Katzenberg (who created the scripted MTV series The Hard Times of RJ Berger), Nicky has been leaning on her older sister Paris for support.
"Paris has a house in Malibu, so I`ve just been spending time relaxing there. Paris and I are going to go to the South of France next week for some business and pleasure," said Nicky.