Jay-Z is signing a $20 million deal with Samsung.

The rap star is rumoured to be setting up a music streaming service to help promote acts signed to his Roc Nation label - including Rita Ora, Alexis Jordan and J.Cole - via the company's smartphones.

A source told the New York Post: ''The eight-figure deal will be inked in the next few weeks, and is the biggest of its kind. You can speculate that he'll want to develop some kind of new music-streaming service to promote his acts and music on mobile devices.''

The 43-year-old star and his wife, Beyonce, were spotted backstage at the Hot 97's Sunday Summer Jam at MetLife Stadium this weekend, which was billed as 'The Biggest Hip-Hop Show on Earth'.

The power couple then partied at New York City's W.i.P. club until 3.30am yesterday (03.06.13), holding court at two tables with rappers Fabolous, Miguel, Wale, Meek Mill, Busta Rhymes and Omarion.

Jay-Z isn't the only one making mega bucks from business deals in his family. Beyonce signed a $50 million contract to become the new face of Pepsi last year.

The lucrative deal saw her grace a series of limited edition cans of the fizzy drink, with Pepsi also sponsoring many of her concerts and helping promote her forthcoming fifth studio album, set for release in November.