Leonard Riggio, chairman of Barnes & Noble Inc., may consider bidding for the firm's bookstore business, sources said.

Riggio, the company's biggest shareholder with almost 30% stake, is expected to take the 689 retail stores private that would separate the business from its college store chain and Nook e-reader and tablet business, according to people familiar with the matter.

The retail business of Barnes & Noble has long been struggling from the shift of consumers to digital formats, which attributed to its poor revenues at 10.9% at all of its divisions in 2012, the year when it announced its plan to restructure and e-reader business.

Earlier in February this year, the company reported that it expects more decline in its sales for Nook, which it launched in 2009 to compete with the market-leading Kindle of Amazon.com.