A number of private equity firms are interested in taking a look at Barnes & Noble, with names including Bain Capital, Apollo, TPG Capital and others, sources familiar with the matter said.

Still, it was unclear how any private equity interest might be structured, given that billionaire investor Ron Burkle and company founder Leonard Riggio have large shareholdings in the bookseller. It was also unclear the level of interest or whether any bids will materialize, the sources said.

The No. 1 U.S. bookstore chain, which has a market value of about $900 million, said on Tuesday it was reviewing strategic alternatives including a possible sale, and could get a bid from founder Riggio as part of a larger investor group.

Private equity firms have in the past had an interest in bookshops. In 2006, TPG, Bain, Apollo and Leonard Green Partners considered bidding for bookstore chain Borders Group Inc., according to a Financial Times report at the time.

Buyout firms have recently been pursing smaller deals than the multi-billion dollar transactions they are famed for, as financing after the credit crisis became more expensive.