Booktrope plans to go out of business at the end of May, bringing an end to its “team publishing” platform used by ad hoc groups of authors, editors, marketers and designers to create and market print books and e-books.

The Seattle startup, which went through the prestigious Y Combinator accelerator program, announced the news Friday in a message on its site and a detailed email to users from the company’s executives.

“Much has been accomplished by Booktrope and our community over the past six years,” read the email from CEO and co-founder Ken Shear; co-founder and CTO Andy Roberts; and COO Jennifer Gilbert. “But even with a collection of excellent books and with very strong contributions by creative teams who’ve provided editing, design and marketing services, Booktrope books have not generated sufficient revenues to make the business viable.”

The company raised $1.2 million in seed funding a year ago, which co-founder and chief marketing officer Katherine Sears described at the time as the culmination of its participation in Y-Combinator — “where we were the oldest founders in their history,” she noted. Khosla Ventures was the lead investor in the round.

Booktrope says in a message on its site: “We are deeply saddened to report Booktrope is ceasing business effective May 31, 2016. We are not accepting submissions and production is complete.

“Booktrope has helped hundreds of authors get over 4 million copies of their books into the hands of readers. We are proud our creative teams have produced almost 1000 books using our platform. Thank you to all readers, authors, investors, partners, and creative team members who were a part of this journey with us.”

The company connected authors with editors, cover designers, proofreaders and marketers to create and promote e-books and print books. Teams managed the process and collaborated using the company’s “Teamtrope” platform. Booktrope helped to get books published and distributed in print and as e-books, and managed financial and legal issues.

Booktrope kept 30 percent of the net profits, and the creative teams split the remaining 70 percent based on agreements among them. Booktrope didn’t charge any up-front fees.

Booktrope had 11 employees as of last month. Sears, the company’s chief marketing officer, went on a leave of absence recently for personal reasons. We’ve contacted Sears and the other co-founders for additional information about the decision to cease operations.

With the closure, Booktrope says it will “remove all published books from sale as of May 31, 2016,” returning rights to authors as of June 1, except for titles currently in the Amazon Encore program. Booktrope struck a licensing deal with Amazon in 2014 to reissue some of its books through Amazon Publishing.

The company’s email to its “Tropers” outlined the process for paying out final royalties to authors and other team members, and said it would be providing more detailed information in blog posts starting next week.