Gibson, Dunn & Crutcher is representing Dallas-based hospital operator Tenet Healthcare Corp., which said Monday it has agreed to acquire smaller rival Vanguard Health Systems—itself advised by Skadden, Arps, Slate, Meagher & Flom—in a deal worth $4.3 billion, including assumed debt.

Also announced Monday was buyout firm KKR's purchase of Raleigh, N.C.–based PRA International, which performs clinical laboratory tests for pharmaceutical and biotechnology companies, from Genstar Capital. KKR is represented by frequent counsel Simpson Thacher & Bartlett in that deal—worth a reported $1.3 billion, according to The New York Times—while Latham & Watkins is advising PRA and Genstar.