NEW YORK — Barnes & Noble Inc. shares fell Thursday after the retailer said it expects losses from its Nook e-reader business to be larger in 2013 than they were last year.

The largest traditional US bookseller has invested heavily in the Nook as more consumers shop online and read e-books. But the Nook faces tough competition from devices like Apple’s iPad Mini, Amazon’s Kindle, and Google’s Nexus tablet.

Barnes & Noble said it expects Nook media revenue of less than $3 billion. It also anticipates a loss for the unit from earnings before interest, taxes, depreciation, and amortization to exceed the $262 million loss recorded in its 2012 fiscal year.

This follows a report from the retailer in January that its Nook unit revenue fell 12.6 percent to $311 million during the critical holiday period.

The shares sank $1.06, or 7.4 percent, to $13.14.

The company said late Wednesday that it will report third-quarter fiscal 2013 results before the market opens Feb. 28, and that the news will not be good — particularly for the Nook digital unit.

Last year, Barnes & Noble signaled its commitment to a digital future by investing heavily in a tablet to compete with products from Google, Apple and Amazon.com.