THL Closes Flagship Fund X

THL Partners has closed its latest flagship fund, THL Equity Fund X LP, with $6.35 billion in capital.
Limited partners in the new fund include a mix of existing and new investors, including public and corporate pension funds, sovereign wealth funds, financial institutions, and family offices across North America, Latin America, Europe, Asia, Australia, and the Middle East.
With the close of Fund X, Boston-based THL has now raised over $50 billion of equity capital since its founding in 1974. The firm’s earlier fund, Thomas H. Lee Equity Fund IX LP, closed in October 2021 with $5.6 billion in capital.
Scott Sperling
“We are grateful for the continued support of our long-standing limited partners and are also pleased to welcome new investors to Fund X,” said Scott Sperling, a co-chief executive of THL. “We value the strength of our long-term partnerships and the collaboration they enable across our platform.”
THL was founded in 1974 and is one of the oldest private equity investment firms in the United States. Industries of interest include financial technology and services, healthcare, and technology and business solutions.
Last month, THL agreed to acquire Celerion, a portfolio company of H.I.G. Capital and a Nebraska-based provider of clinical research services that helps drug companies test new treatments in early development. The company runs studies on how drugs behave in the body, including initial human testing, safety assessments, and interactions with other drugs, generating data needed for regulatory approval.
“Celerion plays a critical role in bringing new medicines to market, particularly at the earliest and most complex stages of clinical pharmacology,” said Megan Preiner, a managing director at THL. “With its differentiated clinical infrastructure, leading scientific expertise, and strong customer relationships, Celerion is one of the few organizations globally to integrate clinical pharmacology and bioanalytical capabilities under one roof—a combination that is increasingly valuable as drug development grows more complex.”
Todd Abbrecht
“We believe our focused strategy, built on deep sector expertise and operational engagement, positions us well to partner with management teams and drive sustainable growth and long-term value creation,” said Todd Abbrecht, a co-chief executive of THL.
Since its founding, THL has acquired over 175 portfolio companies and completed over 700 add-on acquisitions, with a combined enterprise value exceeding $260 billion.