After 57 years in business, the Penn Book Center in University City will close in May.

In a statement on Monday, owners Ashley Montague and Michael Row attributed the closing to “losses due to the explosion of online sales of books at cut-rate prices.”

Penn Book Center was founded in 1962 by Achilles, Olga, and Peter Nickles as an independent bookstore on the University of Pennsylvania campus. It was one of the city’s oldest independent bookstores and was celebrated for its selection, especially in hard-to-find titles that appealed to college buyers. In 2005, Achilles and Olga Nickles sold the store to Montague and Row.

In recent years, the store had moved away from textbooks, increased in-store events, changed its layout, sponsored book clubs, and extended hours. It hosted more than 125 events in 2018. In the statement, Montague said that the changes “have not generated the sales we need to stay open."

The Penn Book Center is not to be confused with the University of Pennsylvania Bookstore, operated by Barnes & Noble. The owners of Penn Book Center said markdowns will begin this month and events will be hosted through May.