Roc Nation Sports, the sports agency founded in April by Jay-Z, on Monday officially scored its most marketable name in Oklahoma City Thunder forward Kevin Durant.

The firm's spokesman Ron Berkowitz confirmed the news, and Durant later tweeted out a picture on Monday afternoon of he and Jay-Z signing the papers. ESPN.com initially reported on June 8 that the partnership was expected.

Kevin Durant and Jay-Z sign papers to finalize the star forward's association with Roc Nation Sports. Roc Nation

"Grateful for this opportunity with Roc Nation Sports," Durant said, in the text above the tweeted picture. "It's go time."

"He has a 90.5 free throw shooting rate, the youngest player in NBA history to join the 50-40-90 club," Jay-Z was quoted as saying, above the picture. "A giving individual and a legend in the making. What more can I say?"

The move was expected for two weeks, since Durant told his former agent Rob Pelinka that he was jumping ship and wanted to try partnering with the power of Jay-Z.

The partnership will immediately test Jay-Z's ability to score out-of-the-box marketing deals.

After all, Durant is one of the most bankable athletes in all of sports, having endorsement deals with Nike, Sprint, Gatorade, Skullcandy headphones, BBVA Compass, 2K Sports and Panini America.

Although Durant will be a full client of the firm, he doesn't need a contract agent because he signed an $85 million extension with the Thunder in 2010 that will take him through the 2015-16 season.