Founded in 2019, Westbrook has backed projects including the recent film “King Richard,” a biopic chronicling the life of

Richard Williams,

the father of tennis stars

Venus

and

Serena Williams.

Other Westbrook projects include the “Fresh Prince of Bel-Air” reunion on HBO Max and “Red Table Talk,” a show on

Facebook

Watch featuring Ms. Pinkett Smith, her daughter

Willow Smith

and her mother,

Adrienne Banfield-Norris.

“Westbrook is the realization of our dream to give artists from all backgrounds equal opportunities to pursue their creative visions and share their stories,” Ms. Pinkett Smith and Mr. Smith said in a statement. “We are pleased to join forces with Kevin, Tom and Blackstone to accelerate this mission by growing our content pipeline, our talent network, and our global expansion plans.”

The Westbrook deal is the latest in a series of acquisitions in recent months for Messrs. Mayer and Staggs’s venture.

In November, the firm said it was buying Moonbug Entertainment Ltd., the company behind hit children’s shows “CoComelon” and “Blippi,” for about $3 billion. In August, it said it was spending $900 million to acquire Hello Sunshine, the media company founded by

Reese Witherspoon.

Mr. Mayer told The Wall Street Journal in August that he and Mr. Staggs were creating a new entertainment company for Hollywood’s streaming era. Some media companies are reluctant to license shows and movies to rivals, Mr. Mayer said, creating an opportunity for a new, independent player.

Hollywood has seen a glut of deals in recent months as buyers cash in on the demand for movies and TV shows for new streaming services.

CJ ENM,

South Korean media company behind Academy Award winner “Parasite,” in November agreed to purchase a majority stake in Endeavor Content’s scripted entertainment business for between $900 million and $1 billion, the Journal reported.

SpringHill Co., an entertainment company co-founded by National Basketball Association star LeBron James, agreed in October to sell a majority stake to a consortium of investors that valued the business at $725 million.

Write to Benjamin Mullin at Benjamin.Mullin@wsj.com and Miriam Gottfried at Miriam.Gottfried@wsj.com