Basketball star LeBron James is joining forces with renowned hedge-fund manager John Henry and veteran Hollywood producer Tom Werner in a deal that brings together one of the biggest stars in sports and two of the worlds most renowned teams.

The deal between Mr. James and Fenway Sports Group will give Mr. James a minority interest in the soccer club Liverpool, which FSG owns. FSG, which also owns the Boston Red Sox, is partnering with Mr. Jamess sports-marketing firm, LRMR Branding & Marketing to become the exclusive world-wide representative for Mr. James.

The deal marks the first time that a professional athlete at the top of his game has taken an ownership interest in a team with the size and reach of Liverpool, which is one of the most popular and powerful sports teams in the world.