Barnes & Noble
A Barnes & Noble bookstore Reuters

Barnes & Noble's CEO William Lynch stepped down late Monday afternoon as the bookstore chain gets out of the tablet business.

Lynch also resigned from the board of directors, effective immediately. He's departing after a three-year tenure in which Barnes & Noble was battered by the shift away from brick-and-mortar bookstores to e-commerce and digital products.

The statement from Barnes & Noble (NYSE:BKS) didn't explain the reason for the abrupt change and declined to elaborate on the statement. Spokeswoman Mary Ellen Keating said the company "is in a transition period, so we have we have no immediate plans to name a new CEO."

The New York-based company is in the midst of operational changes to reinvigorate its book-selling business while overhauling the digital strategy.

Last month, Barnes & Noble said it was looking to cut back on losses in the Nook unit by ending manufacturing of its color tablets, a competitive field where it trails Apple's (Nasdaq:AAPL) iPad, Amazon's (Nasdaq:AMZN) Kindle Fire and others. Nook sales plunged by 34 percent in the last quarter. The company said it is looking for a partner that will co-brand and manufacture its tablets.

Overall, Barnes & Noble reported a quarterly loss last month of $118.6 million, nearly double its loss from a year prior, CNN reports. Revenue fell 7.4 percent to $1.3 billion.

Barnes & Noble says it will continue designing its e-reading devices, including of Simple Touch and Glowlight products, while building out its digital catalog of e-books.

"We thank William Lynch for helping transform Barnes & Noble into a leading digital content provider and for leading in the development of (its Nook line of products)," Chairman Leonard Riggio said in a statement.

In other management changes, Michael Huseby has been appointed CEO of Nook Media and President of Barnes & Noble, and Max Roberts, CEO of Barnes & Noble College, will continue to lead the digital education strategy and report to Huseby.

Shares of Barnes & Noble fell from $17.66 to $16.95 in after-hours trading.