WALTHAM, Mass. — Thermo Fisher Scientific Inc. has agreed to sell its microbiology business to private equity firm Astorg in a transaction valued at approximately $1.075 billion, the company said.
The deal includes a mix of cash and a $50 million seller note, and is part of Thermo Fisher’s ongoing portfolio management strategy aimed at reallocating capital toward higher-growth opportunities.
“The transaction reflects our active management of the company and provides additional capital we can deploy to create shareholder value,” said Marc N. Casper, chairman and chief executive officer of Thermo Fisher. “We believe the microbiology business is an excellent fit within Astorg’s portfolio. We are confident in a smooth transition and wish the business and colleagues continued success after close under its new ownership.”
The microbiology unit provides antimicrobial susceptibility testing and culture media solutions used in clinical diagnostics, pharmaceutical development, and food safety testing. It generated approximately $645 million in revenue in 2025 and operates within Thermo Fisher’s Specialty Diagnostics segment.
The transaction is expected to close in the second half of 2026, pending regulatory approvals and other customary closing conditions.
Thermo Fisher said the divestiture is expected to reduce adjusted earnings per share by $0.15 in the first full year after closing. The company plans to provide additional details on the financial impact during its second-quarter earnings call.
Advisers on the deal include Cravath, Swaine & Moore LLP as principal legal counsel to Thermo Fisher, with Axinn, Veltrop & Harkrider LLP handling regulatory matters and Hogan Lovells serving as international counsel. Perella Weinberg Partners and Wells Fargo are acting as financial advisers.
Astorg is being advised by Evercore and Moelis as financial advisers, with Latham serving as legal counsel.
