NEW YORK — Another major publisher is testing the subscription market.

Macmillan will make 1,000 books available to Oyster and Scribd, the subscription services announced separately Tuesday. The releases, all older works, range from Janet Evanovich's "Full House" to "The Language of Passion" by Nobel laureate Mario Vargas Llosa. Publishers, citing concerns about driving down the value of a book, have been cautious about working with companies such as Oyster, Amazon.com and Scribd that offer unlimited e-reading of hundreds of thousands of releases for less than $10 a month.

Simon & Schuster and HarperCollins also have been working with subscription companies, and the CEOs for both publishers have said they were happy with the results. A spokeswoman for the country's largest publisher, Penguin Random House, said it is "uncommitted at present to offering our books for any subscription services." (The respective parent companies of Penguin Random House and Macmillan, Bertelsmann and the Holtzbrinck Publishing Group, co-founded the German subscription service Skoobe in 2012.)

Financial terms between Macmillan and the subscription services were not disclosed. Last month, Macmillan CEO John Sargent wrote an end-of-year letter to authors, illustrators and agents that disclosed his willingness to try subscriptions despite a "significant long-term risk."

"We need broader channels to reach our readers," wrote Sargent, who referred to Amazon.com's dominance of e-book sales.

"Several companies offer 'pay per read' plans that offer favorable economic terms. We plan to try subscription with backlist books, and mostly with titles that are not well represented at bricks-and-mortar retail stores. Our job has always been to provide you with the broadest possible distribution, and given the current financial and strategic incentives being offered, we believe the time is right to try this test."

Macmillan and other publishers once expressed similar reservations about offering e-books to libraries, but virtually all now make them widely available.