The Mills family, which ascended to the ranks of the world’s wealthiest dynasties after selling Medline Industries last year, is building its own investment firm to deploy its vast fortune.

Medline president Andy Mills, a fourth-generation member of the Chicago-based family, has formed Council Ring Capital and assembled a team to help manage a portion of its wealth, according to a person with knowledge of the matter. Council Ring has about $5 billion in assets, said the person, who asked not to be identified because the information is private.

CIO Chuck Murphy, a former executive at Longview Asset Management, declined to comment.

The Mills were on the receiving end of one of the single-biggest liquidity events of all time when they sold a 79 percent stake in their medical-goods supplier to a consortium of private equity firms in a transaction that valued the company at about $32 billion. The family has maintained a minority stake in Medline, which Andy, his cousin Charles Mills and Andy’s brother-in-law Jim Abrams continue to run.

The company’s roots trace to 1910, when A.L. Mills began sewing butcher aprons for the Chicago stockyards. He expanded to surgeons’ gowns and that enterprise eventually evolved into Medline, which sells medical supplies to thousands of US hospitals.

The family’s collective fortune is valued at $26.2 billion, according to the Bloomberg Billionaires Index.

Council Ring describes itself in a LinkedIn profile as a “Chicago-based, multistrategy investment firm affiliated with a single family,” without identifying the Mills. It “leverages its permanent capital asset base to make long-term investments in publicly traded companies, privately held or sponsor-backed companies, and partnerships with third-party investment funds.”

The investment team includes Judah Milunsky, formerly of Atalan Capital Partners, and Marc Gruenhut, who are focused on technology and health-care bets, respectively, according to LinkedIn.

The number of family offices worldwide has soared over the past two decades due to surging wealth levels and a growing awareness among the super-rich of the benefits of investing through the flexible and lightly regulated entities. Some of the largest, like Michael Dell’s MSD Capital, the Walton family’s Walton Enterprises and Mousse Partners, the investment entity of the family behind Chanel, have grown to become influential investors on a par with institutions like major pension funds or private equity firms.

The collective wealth managed by family offices in North America alone has grown to an estimated $182 billion, according to a November study by RBC and Campden Wealth.