Another Amazon victim -- this time it's Barnes & Noble's CEO

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

It marks the departure of a tech-focused executive who rose to the company's helm from its online business, and puts more authority in the hands of Leonard Riggio, Barnes & Noble's chairman and biggest shareholder.

Through a wave of acquisitions, Riggio built the chain into the country's biggest bookseller, but the company has struggled to find its bearing as Amazon first undermined its traditional book business and then outgunned it on reading devices.