P Diddy has proposed to his long-term girlfriend, Cassie Ventura.

The rap mogul and businessman posted a picture of a huge diamond ring on Instagram over the weekend, which TMZ.com claim is his engagement ring for his girlfriend of seven years.

Next to the picture of the huge rock he wrote: ''Baby do you like it? I just want to get you wat you Like ! I just wanna Mk you smile :) #takeDat. ! (sic)''

Cassie wrote back: ''It's definitely smiling. Its perfect!''

She was later pictured wearing the ring on her engagement finger in a post on the same site by singer Keyshia Cole.

Cassie, 27, is a singer signed to Diddy's Bad Boy records as well as a model who has appeared in campaigns for Calvin Klein, Adidas and Abercrombie & Fitch. She has released two albums, 'Cassie' in 2006) and 'RockaByeBaby' last year.

Diddy - real name Sean Combs - has had a number of high profile relationships, with stars including Jennifer Lopez, and is father to five children. He has son Justin, 20, with his former high school sweetheart Misa Hylton-Brim, 15-year-old Christian and seven-year-old twins D'Lila Star and Jessie James Combs his ex-partner Kim Porter and a seven-year-old daughter, Chance, with Sarah Chapman.

Diddy, 44, is also the informal stepfather of Quincy, 23, Kim's son from a previous relationship.