Blackstone Buys Stake in Certified Collectibles, Joined by Jay-Z

Blackstone Group Inc. agreed to buy Certified Collectibles Group, which grades and verifies items such as sports trading cards, stamps and coins.

Blackstone said its tactical opportunities group is purchasing a majority stake, valuing the business at more than $500 million. Other investors include Roc Nation, Jay-Z’s entertainment company, and Daryl Morey, president of basketball operations for the Philadelphia 76ers. Certified Collectibles founder Mark Salzberg and Chief Executive Officer Steven Eichenbaum will retain a significant minority stake.