Rihanna and 50 Cent are among the stars who have offered their condolences following the death of hip-hop mogul Chris Lighty.

The 44-year-old - who helped the likes of 50, Sean "Diddy" Combs and Mariah Carey attain not only hit records, but also lucrative careers outside music - was found dead in his New York City apartment on Thursday in an apparent suicide.

He was found with a gunshot wound to the head and was pronounced dead at the scene, police said. No note was recovered, but a 9 mm handgun was found and there was no sign of forced entry, said Paul Browne, New York police spokesman. The shooting appears to be self-inflicted, authorities said.

50 Cent said in a statement issued through his publicist that he was deeply saddened by the loss.

"Chris has been an important part of my business and personal growth for a decade," he said. "He was a good friend and advisor who helped me develop as an artist and businessman. My prayers are with his family. He will be greatly missed."

"Rhode IslandP. Chris Lighty," Fat Joe posted on his Twitter account. "The man that saved my life!"

Diddy wrote: "In shock."

Rihanna posted: "Rest peacefully Chris Lighty, my prayers go out to family and loved ones! Dear God please have mercy."

Mary J Blige wrote: "U never know what can send a person over the edge or make them want 2 keep living. take it easy on people."