“The Hate U Give” was one recent Fox 2000 disappointment, costing roughly $50 million to make and market and collecting $35 million worldwide last year, about half of which went to theater owners.

“This re-establishes us as a big buyer,” Ms. Gabler said in an interview, referring to her all-female Fox 2000 team, which she will take with her to the new division. (There are 10 executives and assistants.)

Ms. Gabler emphasized that her new Sony label would also develop films based on books from publishers other than HarperCollins and that she could make movies for third-party distributors if Sony passed. For the first time, she will also be able to develop books for television, including Netflix and other streaming services.

Brian Murray, chief executive of HarperCollins, came up with the idea of joining forces with Sony.

“We thought we could play a greater role as a facilitator, increasing the odds that HarperCollins authors could see their books turned into compelling films, television, streaming opportunities,” Mr. Murray said in an interview. With the rise of streaming, there is been a steep increase in the number of books being developed for films or shows, he noted. Netflix alone will spend roughly $8 billion on original content next year, according to BTIG Research. Hulu and Amazon are expected to spend an estimated $3 billion apiece.

Sony said Ms. Gabler’s focus on new books as sources for modestly budgeted films made her a must-have executive, complementing the studio’s primary business of big-budget remakes, spinoffs and sequels. Sony’s most recent movie, “Spider-Man: Far From Home,” is on a pace to collect at least $1.1 billion worldwide.