Hedge fund Elliott Management announced Friday it plans to acquire bookseller Barnes & Noble for roughly $683 million, including debt.

Barnes & Noble has faced continued pressure from Amazon and independent booksellers. Its shares had fallen roughly 25 percent year to date before news of the deal leaked on Thursday. Within the past five years, Barnes & Noble has lost more than $1 billion in market value.

Amazon holds nearly half of new book sales, a report by audience research Codex Group said last year, while Walmart has about 4.2 percent of the market

In search of a turnaround, Barnes & Noble said last year it was exploring a sale after having received “expressions of interest” from “multiple parties,” including its chairman, Leonard Riggio, who founded the company in 1965.

Riggio has entered into a voting agreement in support of the transaction, the company said Friday.

As a private company, Barnes & Noble will likely be more free to make the changes and investment that can be unwieldy under a public spotlight. Part of the bookseller’s turnaround plan has included closing some of its more than 600 stores across the U.S. and relocating to smaller spaces that receive a fresh and modern look. The company has said its prototype stores encourage shoppers to buy books online or from a tablet.

The retailer has shown small signs of upturn. In March, it reported that over the holidays, sales at locations open for at least a year during the quarter rose 1.1 percent — its best quarterly performance in three years.

For its part, Elliott, the firm founded and led by billionaire Paul Singer, acquired Britain’sbiggest bookseller, Waterstones, last year. Owning the two book retailing giants could give Elliott synergies and buying leverage with publishers, people familiar with the industry say.

Elliott will operate the two retailers independently, the company said on Friday, though Waterstones CEO James Daunt will oversee both retailers as chief executive.