Thermo Fisher Scientific has agreed to divest its microbiology division to private equity firm Astorg in a deal valued at approximately $1.08bn, according to a company statement. The transaction is being made via Astorg VIII and represents the funds’ tenth investment to date.
The business being sold focuses on antimicrobial susceptibility testing and culture media, with applications spanning clinical diagnostics, pharmaceutical development, and food safety.
Currently housed within Thermo Fisher’s specialty diagnostics segment, the microbiology unit generated revenues of $645 million in 2025.
Chief executive Marc Casper said the sale is part of the company’s ongoing portfolio optimisation strategy, aimed at reallocating capital toward opportunities that enhance shareholder returns.
Completion of the deal is anticipated in the second half of 2026. Thermo Fisher indicated that the divestment is expected to reduce adjusted earnings per share by $0.15 in the first full year following closing.
