Barnes & Noble Chief Executive William Lynch has resigned, following the bookseller's long fight for a Nook tablet that rivals Amazon's Kindle.

"I appreciate the opportunity to serve as CEO of this terrific Company over the last three years," Lynch said in the release. "There is a great executive team and Board in place at Barnes & Noble, and I look forward to the many innovations the Company will be bringing to its millions of physical and digital media customers in the future."

The company did not provide a reason for Lynch's departure.

The book retailer is naming Michael Huseby as president of the company and chief executive of its Nook Media unit.

The management changes come just weeks after Barnes & Noble posted a wider net loss and said sales plunged in the three months ended April 30, with revenue at stores open at least a year dropping 8.8 percent.

Overall retail sales, which include Barnes & Noble bookstores and online sales, declined 10 percent, in part because of store closings.

Shares of Barnes & Noble were down 3.6 percent in after-hours trading.