Jay-Z's Roc Nation joins Blackstone in takeover of $500 million collectibles company

• Blackstone is acquiring the Certified Collectibles Group in a transaction valuing the company at more than $500 million.
• Jay-Z's Roc Nation is also an investor in the transaction.
• CCG offers authentication services for collectibles items including comic books, stamps, and trading cards.

Blackstone has agreed to acquire a majority stake in the Certified Collectibles Group in a transaction valuing the company at more than $500 million, the private equity firm said Thursday.

Jay-Z's Roc Nation will be an investor in the transaction, as well as Michael Rubin, founder and executive chairman of Fanatics, NBA player Andre Iguodala, Daryl Morey, President of Basketball Operations for the Philadelphia 76ers, and others.

The Certified Collectibles Group (CCG) offers authentication services for various collectibles items including comic books, banknotes, magazines, concert posters, stamps, trading cards, sports cards and estate items.

CCG estimates it has certified more than 62 million of these collectibles, with a combined fair market value approaching $50 billion.

Specifically, Blackstone's funds managed by its Tactical Operations business will be acquiring a majority stake in the collectibles company. Meanwhile, CCG founder Mark Salzberg and CCG CEO Steven R. Eichenbaum will retain a "significant minority stake," the company said.

Blackstone seeks to develop CCG's digital presence, add employees, and branch CCG's geographic reach.

Shares of Blackstone were up 0.3% Friday.