HarperCollins, one of the Big Five publishers in the US, has made a deal to acquire Houghton Mifflin Harcourt Books and Media, the trade publishing division of Houghton Mifflin Harcourt, for $349 million. The acquisition will help HarperCollins expand its catalog of backlist titles at a moment of growing consolidation in the book business. Houghton Mifflin publishes perennial sellers by well-known authors such as J. R. R. Tolkien, George Orwell, Philip Roth, and Lois Lowry, as well as children’s classics and best-selling cookbooks and lifestyle guides.