Multichannel books retailer Barnes & Noble Inc. is exploring several new strategic options, including putting the company up for sale.

In a new regulatory document Barnes & Noble filed today with the U.S. Securities and Exchange Commission, the retailer says it formed a special independent committee made up of four directors that will evaluate several strategic options, including a possible sale. Barnes & Noble, No. 42 in the Internet Retailer Top 500 Guide, named George Campbell Jr., William Dillard, II, Margaret Monaco and Patricia Higgins as independent directors to oversee the evaluation. No timetable has been set for any sale.

Barnes & Noble is looking at various strategic options in light of what it considers its undervalued stock. “As the world’s largest bookseller, Barnes & Noble has an iconic brand and unique competitive advantages we believe will position the company to succeed over time in a rapidly changing market,” the company says in its SEC filing. “The board is confident in Barnes & Noble’s strategy and fully supportive of the senior management team, which is delivering explosive growth in our fast-developing digital business. The board has concluded that a review of strategic alternatives is the appropriate next step to take full advantage of our compelling digital opportunities and to create value for shareholders, customers, and employees.”

In light of exploring more strategic options, the retailer’s biggest single shareholder, founder Leonard Riggio, is looking into purchasing Barnes & Noble. “Leonard Riggio has informed the board that, in light of its decision to explore strategic alternatives, he intends to consider the possibility of participating in an investor group to acquire the company,” says Barnes & Noble.

Barnes & Noble, which is tying its future to more e-commerce, digital content and Nook, its electronic book reading device, increased its e-commerce revenue 24% to $573 million in fiscal 2010 from $462 million in fiscal 2009.