Hachette Book Group said on Monday that it had agreed to buy Workman Publishing, an independent company known for titles like “What to Expect When You’re Expecting” and the “Brain Quest” workbooks, the latest expected acquisition in an industry whose power is increasingly concentrated in a handful of major companies.

Hachette and Workman declined to disclose the price of the deal, but Michael Pietsch, Hachette’s chief executive, said in an interview Monday morning that Workman marked his company’s biggest acquisition in the past eight years. It was also the biggest investment its parent company, Hachette Livre, has made since creating Hachette Book Group 15 years ago. Hachette said it didn’t plan to cut any jobs as a result of the deal.

In the decades since its founding, Workman became a leading publisher of nonfiction and advice and how-to brands. Its “Brain Quest” series of educational games and workbooks has more than 45 million copies in print. With its literary imprint, Algonquin Books, Workman has had breakout literary successes like Sara Gruen’s “Water for Elephants,” Tayari Jones’s “An American Marriage” and Lisa Ko’s acclaimed debut novel, “The Leavers.”