Shearman & Sterling is representing Quest Diagnostics Incorporated, the world’s leading provider of diagnostic testing, information and services, in its definitive agreement to acquire Athena Diagnostics, an esoteric laboratory specializing in genetic testing for neurological disorders, from Thermo Fisher Scientific for $740 million in cash. The transaction is expected to be completed early in the second quarter of 2011 following the satisfaction of customary conditions.

Quest Diagnostics is the world’s leading provider of diagnostic testing, information and services that patients and doctors need to make better healthcare decisions. Athena Diagnostics, founded in 1988 and based in Worcester, Massachusetts, is the leading provider of advanced diagnostic tests used to rule out, or confirm, physicians’ diagnoses of neurological conditions, such as Alzheimer’s disease, neuromuscular disorders, such as spinal muscular atrophy, and developmental disorders.

The Shearman & Sterling team was led by partner Clare O’Brien (New York-Mergers & Acquisitions) and also included partners Larry Bambino (New York-Tax), Doreen Lilienfeld (New York-Executive Compensation & Employee Benefits), and Tina Patel (Menlo Park-Intellectual Property Transactions) and associates Dorman Yale (New York-Mergers & Acquisitions), Kristopher Ferranti (New York-Mergers & Acquisitions), Amy Lewis (New York-Tax), Meghan Moore (New York-Executive Compensation & Employee Benefits) and Tim Franklin (New York-Intellectual Property Transactions).