Barnes & Noble Inc. gained the most in 11 months after Jana Partners LLC, a hedge fund that has pushed for companies to sell off assets, disclosed a 12 percent stake in the largest US bookstore chain.

The New York-based retailer rose 18 percent to $13.41 at the close in New York for the largest gain since May 20. The shares have declined 7.4 percent this year.

Barnes & Noble is considering separating its growing Nook digital unit into a separate company so investors will give it the higher valuation of a technology business. In March the company hired a new chief financial officer, Michael Huseby.