In 2004, Shaquille O'Neal earned $27.7 million in the NBA — it was his best-paid year in basketball. But post-NBA the hall-of-famer has actually been making more money each year than he did in basketball through his various investments and endorsements deals.

And now, after building a sprawling business empire full of restaurant franchises, fitness gyms, car washes, his own line of branded products and partnerships with Papa John's and Carnival Cruise Line to name a few, O'Neal says he is ready for his next move — to buy iconic sneaker brand Reebok.

"Well, [Authentic Brands Group, one of the companies] I'm involved in, we just bought Sports Illustrated but I would love to purchase Reebok," O'Neal, aka, Shaq, tells CNBC Make It at a Carnival Cruise event on Tuesday.

In 2015, O'Neal sold Authentic Brands Group (ABG) the rights to his future business endeavors (like merchandise and endorsements) for an undisclosed amount. Under the deal, O'Neal became a business partner in the private company, which has a portfolio that includes more than 50 customer brands and as well as celebrity licenses, like those of Marilyn Monroe, Elvis Presley, Muhammad Ali and Michael Jackson.

O'Neal, who has a long history with Reebok, first signing a multi-year deal with the shoemaker worth $15 million in 1992, says he wants to buy the company because Adidas — its owner since 2005 — has "diluted [the brand] so much to where it's almost gone."

"If they don't want it, let me have it," O'Neal says. "I want to bring them back to basketball and to fitness."

He says he remembers back in the day when he was a spokesperson for the brand, Reebok was thriving and neck and neck with Nike. Now he says with more competition from brands like Adidas and Under Armour, the shoemaker, which was founded in 1958, is struggling to find its way. And he thinks he can fix it.

O'Neal could be onto something. In March, Reebok said its classic sneakers from the 1980s and 1990s are making a comeback among millennials, according to Fast Company.

Over the last five years, the company said it has seen consecutive double-digit growth in its Classics business, which recreates iconic sneakers from the past, and it now makes up around 40% of Reebok's total sales, outpacing its performance shoe division.

What's more, Adidas was reportedly considering divesting itself of the brand after revenue for Reebok fell 3% last year, according to Bloomberg.

A spokesperson for Adidas did not respond to CNBC Make It's request for comment.

Reebok would likely be a multibillion-dollar deal. While the exact value of Reebok today is unknown, 14 years ago, Adidas bought the shoemaker for $3.8 billion.

In 2016, O'Neal was worth $400 million, according to Forbes. And ABG's total brand portfolio, not including its licensing deal, generates nearly $8 billion in retail sales a year, according to Women's Wear Daily.

O'Neal says when he decides that he wants to invest or buy a company, he typically follows one rule: "I'm going to invest in things that are going to change people's lives," he told CNBC last year, adding, "my style is very simple."

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