Robin Desser, the editorial director of the Penguin Random House imprint Alfred A. Knopf, will fill Mr. Ward’s role and become senior vice president and editor in chief of Random House. At Knopf, Ms. Desser was a tastemaker who acquired and edited works by best-selling and award-winning authors like Chimamanda Ngozi Adichie, Edwidge Danticat, Jhumpa Lahiri, Valeria Luiselli, Julia Phillips, Arundhati Roy, Jane Smiley, Patti Smith and Cheryl Strayed. In a note to staff, Sonny Mehta, Knopf’s chairman and editor in chief, said that some of the books Ms. Desser edited are “destined to become classics” and praised her for “the joy she takes at working in the editorial trenches.”

The changes come during a period of rapid transformation at Penguin Random House, which has more than 275 imprints and is by far the biggest of the “big five” publishing companies in the United States. In the past year or so, a parade of high-profile editors have left Penguin Random House, among them Molly Stern, the publisher of Crown, who edited Michelle Obama’s book; Julie Grau and Cindy Spiegel, who left the company when their influential imprint, Spiegel & Grau, was shut down; Maya Mavjee, the former president and publisher of Crown, who left Crown when the company decided to merge Random House and the Crown Publishing Group; and Anne Messitte, the former executive vice president of Knopf Doubleday and publisher of Vintage/Anchor, who departed after a restructuring . Ms. Messitte was known throughout the industry as a powerhouse who worked with authors like E L James , Dan Brown, Margaret Atwood, Toni Morrison and Haruki Murakami.

All the churn seems to have done little to shake the company’s dominant position within the industry. Penguin Random House has been on a growth spree: In May it acquired a 45 percent stake in Sourcebooks, an independent publishing company, and in March it acquired the children’s publisher Little Tiger Group. It also bought two publishing companies based in Spain, a Spanish-language literary publisher named Ediciones Salamandra and a Catalan-language publisher , La Campana Llibres . Penguin Random House reported a 33 percent rise in profit for the first half of 2019 compared to the same period the previous year, a jump that was attributed to its acquisitions and a string of best sellers like Mrs. Obama’s memoir and Delia Owens’s novel “Where the Crawdads Sing.” In November, the company said it would add a new distribution center in Reno, Nev., expanding its distribution capabilities on the West Coast.