Barnes & Noble Inc. has received an unsolicited $1.02 billion offer from John Malone's Liberty Media Group, the No.1 bookstore chain in the United States said Thursday.

Liberty Media has offered $17 per share or 20.5 percent premium over Barnes & Noble's closing price on Thursday.

The bookstore chain said its special committee has not yet evaluated the offer. A decision will be taken soon and an announcement will be made, it said.

Barnes & Noble had put itself up for sale last August after saying its shares were undervalued.

The company, which operates 720 brick-and-mortar bookstores as well as a chain of college campus stores, is financially struggling because of declining print book sales.

No.2 bookstore chain Borders Group had filed for bankruptcy in February, after years of shriveling sales and a heavy debt burden. It is currently soliciting offers for a sale but till now no buyer has expressed interest in purchasing all of its outlets.