NEW YORK — Rapper Jay-Z and Lance "Un" Rivera — the record executive he allegedly stabbed at a Manhattan nightclub two weeks ago — had a personal and business relationship prior to the incident, according to a Rivera associate.

Rivera, the head of Untertainment and Un Rivera Productions, co-produced a song that was recorded for Jay-Z's fourth album, which is due Dec. 28.

In the liner notes of an advance copy of Jay-Z's Vol. 3 ... Life and Times

of S. Carter LP, Rivera received a co-production credit for the song

"Dope Man," which also featured production by partners DJ Clue and Duro

and Rivera associate Darrell "Digga" Branch. The track features guest

vocals from MTV News anchor Serena Altschul. Rivera, however, is the only

producer or fellow rapper who worked on the album whom Jay-Z does not

acknowledge in the "Thank You" section of the notes.

"[Rivera and Jay-Z] definitely had a working relationship," Erin Burke, a spokesperson for Rivera, said. "They knew each other for a long time. They both grew up in Brooklyn together.

"Biggie [Smalls, a close friend and business partner of Rivera] and Jay-Z

worked on albums together," Burke continued.

The 29-year-old Jay-Z (born Shawn Carter) was arrested Dec. 2, following an altercation at the Kit Kat Club in Manhattan the night before. Police suspect Jay-Z of stabbing Rivera in the back and chest and hitting him over the head with a bottle. Rivera was treated at a hospital and released the next day. The rapper faces up to 25 years in prison if he is convicted.

The attack on Rivera came two hours after Jay-Z performed at a listening party for Vol. 3 ... Life and Times of S. Carter at Irving Plaza. Employees at the Kit Kat Club, where a listening party for rapper Q-Tip's latest album was taking place, have said that Jay-Z was at the club that night with Ice-T, Eve, Sean "Puffy" Combs and other hip-hop artists.

Reports in the New York Daily News and Newsweek have quoted anonymous sources as saying Jay-Z suspected Rivera of pirating copies of S. Carter. Burke and Brian Senft, a police detective investigating the case, would not comment on those reports. Gabrielle Peluso, Jay-Z's publicist at Def Jam, could not be reached for comment.

Last week Jay-Z's defense attorney, Murray Richman, said he had acquired

a videotape recorded on Dec. 1 at the Kit Kat Club that shows Jay-Z standing to the side during the fight. He said he would not turn over the videotape to investigators until later this week. Richman successfully defended rapper DMX against sodomy charges in New York last year.

The availability of Jay-Z's new album on New York streets has prompted Roc-a-Fella Records, the label he co-runs, to replace three songs with new ones. A label spokesperson would not say which songs were removed.

S. Carter follows last year's Vol. 2 ... Hard Knock Life, which featured the singles "Hard Knock Life" (RealAudio excerpt) and "Can I Get A ..." The album went triple-platinum and established Jay-Z as a hip-hop star.