Thermo Fisher Scientific Inc. (NYSE: TMO) signed a definitive agreement to sell its microbiology business to Astorg, a European private equity firm, for approximately $1.075 billion in cash and a $50 million seller note, according to a company statement.

The microbiology business provides antimicrobial susceptibility testing and culture media solutions for clinical, pharmaceutical and food safety testing. The business generated $645 million in revenue in 2025 and operates within Thermo Fisher's Specialty Diagnostics segment.

"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.

Thermo Fisher expects to close the transaction in the second half of 2026, subject to customary closing conditions and regulatory approvals. The company anticipates the transaction will be dilutive to adjusted earnings per share by $0.15 in the first full year following the close.

Cravath, Swaine & Moore LLP serves as principal deal counsel for Thermo Fisher, with Axinn, Veltrop & Harkrider LLP as regulatory counsel. Perella Weinberg Partners and Wells Fargo serve as financial advisors. For Astorg, Evercore and Moelis act as financial advisors, with Latham serving as legal counsel.

Thermo Fisher will provide details on the expected impact to its 2026 financial outlook during its second quarter earnings call. The company reported annual revenue over $45 billion.