Russell Simmons, who helped bring hip-hop into the mainstream with Def Jam Recordings, said Thursday he was quitting his business empire after fresh allegations of sexual abuse.

The 60-year-old -- who unlike many in the rap world had until recently an uncontroversial public image -- disputed the latest claim against him but said he viewed the mounting public spotlight on sexual misconduct to be "a time of great transition."

"The voices of the voiceless, those who have been hurt or shamed, deserve and need to be heard," Simmons said in a statement.

"As the corridors of power inevitably make way for a new generation, I don't want to be a distraction so I am removing myself from the businesses that I founded," he said.

The announcement came after "Rachel Getting Married" screenwriter Jenny Lumet said that Simmons assaulted her in 1991 when she was 24 and he was a decade older.

Writing in The Hollywood Reporter, Lumet said Simmons forced her into his New York apartment, with his driver refusing her pleas to be taken to her own home, and had sex with her even though she said no.

In his statement, Simmons said he remembered the evening differently but acknowledged that "her feelings of fear and intimidation are real."

"While I have never been violent, I have been thoughtless and insensitive in some of my relationships over many decades and I sincerely and humbly apologize," he said.

Simmons earlier denied accusations by model Keri Claussen Khalighi that he assaulted her in 1991 when she was 17.

Simmons and fellow producer Rick Rubin founded Def Jam in the mid-1980s as hip-hop became a growing force, signing acts such as the Beastie Boys, LL Cool J and later Public Enemy who brought rap to a wide US audience for the first time.

Simmons also promoted Run-D.M.C., the trailblazing rap trio which included his brother Joseph.

While stepping back from music production, Simmons has remained active in entertainment promotion with his Rush Communications firm.

He also runs a fashion brand and a company of yoga apparel and studios.

Simmons, himself a yoga enthusiast, said that a "new and diverse generation" of executives would take over his companies and that he would turn a yoga studio into a "not-for-profit center of learning and healing."

He has also been active in charities, notably supporting animal rights and advocating veganism.