The United Soccer League (USL), an organization that services most of lower-league soccer in the United States, has added a new investor with a big-money background.

BellTower Partners, an firm run by former Carlyle Group CEO Kewsong Lee, has made what the league has termed a “strategic investment,” with the view to strengthen the organization as it prepares to take on Major League Soccer directly in the coming years.

The USL announced earlier this year that it is planning to launch a new US men’s league with first-division sanctioning from US soccer, thus becoming the second such league in the country alongside MLS. Additionally, the organization announced that it would become the first sports league of any type in the US to institute promotion and relegation between its men’s divisions – a hallmark of most soccer leagues worldwide, but not one that has been tried in MLS thanks largely to the league’s single-entity structure.

The USL operates three men’s leagues: the second-tier USL Championship, third-tier League One, and pre-professional League Two. It also operates the Super League (Gainbridge Super League for sponsorship purposes), a D1-sanctioned women’s league that recently started its second season.

The Guardian understands that BellTower’s investment is intended to help the league launch its as-yet unnamed D1 men’s competition and promotion and relegation in 2028. BellTower is acquiring a minority equity stake in the organization and Lee will join the league’s board as vice-chair. However, the USL is not disclosing the size of the investment, the size of the equity stake, or the current valuation of the USL used for the purposes of the investment.

From 2018 until 2022, Lee was CEO of the Carlyle Group, a private equity firm. Lee was co-CEO of the company along with Glenn Youngkin until 2020, when the now-Governor of Virginia left after what Bloomberg called a “long, awkward power struggle.” Lee’s run as CEO took place within a 10-year period in which Carlyle’s portfolio of fossil fuel companies came under scrutiny for their contributions to the climate crisis (claims Carlyle pushed back against).

Reuters reported that Lee earned just over $43m in total compensation from Carlyle in 2021, and that he was paid $3.3m in severance after his departure from the firm.

Since leaving Carlyle in 2022, Lee founded BellTower, which has invested in a number of different companies. This includes Patricof Co, a firm that assists athletes in finding investment opportunities. Patricof counts Travis Kelce and his brother Jason on a lengthy client list that also includes former NFL linebacker JJ Watt, who Patricof helped with an investment in English club Burnley.

To USL, though, the most relevant of BellTower’s investments may be in United Sports Development Partners (USDP), a Connecticut-based real estate developer that specializes in mixed-use projects with a stadium as an anchor. The company was responsible for the development of Centreville Bank Stadium in Pawtucket Rhode Island, the home ground of the USL Championship’s Rhode Island FC.

USDP has also been involved in a $600m proposal for a soccer stadium and mixed-use project in Lee’s home town of Albany, New York – a project that initially had targeted a team in MLS Next Pro, MLS’s reserve league, but shifted focus to USL in early 2025.

Now, six months after that shift, Lee will have a strong foothold in the USL itself.