Private-equity firm Thomas H. Lee Partners (THL) has acquired a significant stake in Chicago-based investment advisory firm HighTower, for an undisclosed sum.

Certain existing institutional investors will sell their equity interests in HighTower in connection with this deal.

Under the agreement, THL will also invest an additional amount $100 m in the investment advisor after this deal is closed.

HighTower offers advisory services to wealth managers across financial services industry and manages around $50bn in client assets.

The deal is expected to close in the fourth quarter of 2017 or first quarter of 2018, subject to regulatory approvals and closing conditions.

HighTower CEO Elliot Weissbluth said: “THL fully supports our mission of delivering objectivity, transparency and independent thinking to investors, while always putting their best interests first.

“Our partnership will help us reach more advisors and clients who refuse to settle for the industry’s status quo.”

THL managing director Ganesh Rao said: “We want to be at the forefront of the changes disrupting the wealth management space, and we proactively sought out HighTower as the ideal partner – they are driving change and have been succeeding at it for a decade.”

HighTower chairman of board of directors Dave Pottruck will continue to be one of the largest individual investors in the firm.