“This goes back to 1990 or ’91 when Bob had quadruple bypass,” said Henry Morrison, the agent for Mr. Ludlum. “One day we were talking about what would happen when he was gone. He said, ‘I don’t want my name to disappear. I’ve spent 30 years writing books and building an audience.’ ”

His estate has borrowed from the examples of V.C. Andrews, dead since 1986 but selling well thanks to novels in her name written by an uncredited author; Ernest Hemingway, whose estates issued several books after his suicide; and Tom Clancy and Clive Cussler (both quite alive) who diverted from their skin of solo thrillers to create series written in conjunction with, or solely by, others.

“People expect something from a Robert Ludlum book, and if we can publish Ludlum books for the next 50 years and satisfy readers, we will,” said Jeffrey Weiner, the executor of Mr. Ludlum’s estate. The estate’s post-mortem publishing game plan is reminiscent of licensing and other deals for dead stars like Elvis Presley, Marilyn Monroe and Babe Ruth, and the film industry’s comfort with familiar franchises.

“Publishing does look to the past to see what will work in the future,” said Sara Nelson, the editor in chief of Publishers Weekly. “Series and big-name authors have tended to work well. Publishers, like executives in other creative fields, want Nos. 2, 3 and 4 to work as well as No. 1. And instead of going off to find the new Ludlum, they figure they’ve got this formula and will continue to use it.”

Image Robert Ludlum in 1986. Since his death in 2001, 12 books with his name have been released. Credit... G. Paul Burnett/Associated Press

Whether it is fair to readers to publish the Ludlum books posthumously — in the form of spruced-up old manuscripts or new novels written by others — is not a serious concern to the estate or to Grand Central Publishing, the former Warner Books, where the rights to all new novels moved from St. Martin’s Press.