By Michael Dabaie

Blackstone Group Inc. said funds managed by its tactical opportunities business agreed to acquire a majority stake in the Certified Collectibles Group.

The investment firm said the transaction values the company at more than $500 million. Blackstone said CCG's founder Mark Salzberg and its CEO Steven Eichenbaum will retain a significant minority stake.

Additional investors in the deal include Roc Nation; Michael Rubin, founder and executive chairman of Fanatics; growth equity platform SC.Holdings; Mastry, founded by Rudy Cline-Thomas; Andre Iguodala; Daryl Morey, president of basketball operations for the Philadelphia 76ers; and Main Street Advisors.

CCG offers authentication, grading and conservation services. Blackstone said it plans to accelerate CCG's growth, enabling the company to invest significantly in its current and planned services, adding and training new employees, expanding its geographic and product reach, acquiring new technologies and developing its digital presence.

Goldman Sachs & Co. LLC acted as exclusive financial advisor to CCG. Duane Morris acted as legal advisor to CCG. Weil, Gotshal & Manges acted as lead legal advisor to Blackstone. Golub Capital led the financing for the transaction.

Write to Michael Dabaie at michael.dabaie@wsj.com

(END) Dow Jones Newswires

07-01-21 1037ET