NEW YORK -- Book retailer Barnes & Noble said its shares have slumped so low that it might put itself on the block, possibly selling the chain to an investment group that would include its founder and biggest shareholder, Leonard Riggio.

The world's largest bookseller said Tuesday that its board is evaluating several options to boost shareholder value in the face of a depressed stock price, including selling the company. Riggio, who holds 28 percent of the company, said he's considering joining an investor group to buy the company.

The New York-based retailer operates 720 stores in 50 states, including several in the Charleston area. The board said there was no specific timeline for the review.

Shares soared on the news in after-hours trading Tuesday, rising $3.31, or nearly 26 percent, to $16.15. Shares closed the regular session down 98 cents, or 7 percent, at $12.84.

The stock has been in free-fall since late June, when the company reported a steep fourth-quarter loss and issued forecasts for first-quarter and full-year net income below expectations.

Barnes & Noble has been hurting, along with other book retailers, as people focus on essentials in the down economy and limit their book purchases. Shoppers also are shifting away from paper books toward electronic books.

Barnes & Noble has been bullish on the future of digital books and introduced its Nook e-reader and its online e-bookstore in October, well ahead of rival Borders. It has been engaged in price wars with Borders and Amazon.com to attract readers to this new market.

Borders, the nation's second-largest book retailer, also has been struggling with falling demand and increasing competition from discounters such as Wal-Mart and online book sellers.

It has been hoping to reinvigorate itself with a $25 million investment from financier Bennett LeBow, who became the company's largest shareholder and chairman and later was named CEO.