Barnes & Noble Inc., facing declining sales at both its bookstore chain and Nook electronic-reader business, agreed to split them into separately traded companies in a bid to improve their performance.

The spinoff will be completed by the first quarter of next year, New York-based Barnes & Noble said in a statement. The company also reported fourth-quarter results today, showing a drop in the bookstore chain’s comparable sales, as well as continuing losses at Nook and lower revenue. Barnes & Noble predicted that sames-store sales would decline in the “low-single digits” this fiscal year.

“We have determined that these businesses will have the best chance of optimizing shareholder value if they are capitalized and operated separately,” Michael Huseby, Barnes & Noble’s chief executive officer, said in the statement. “We fully expect that our Retail and Nook Media businesses will continue to have long-term, successful business relationships with each other after separation.”

The retailer’s shares jumped as much as 14 percent to $23.35. Through yesterday’s close, the stock had added 38 percent this year, fueled in part by takeover speculation.

“The company has not had an easy time over the last couple years,” said John Tinker, a New York-based analyst at Maxim Group LLC. “They’re finally getting to grips with the Nook, they’re now moving ahead in a logical fashion to separate what are very different businesses.”

Samsung Deal

Barnes & Noble had already scaled back investment in the Nook unit and announced plans to team up with Samsung Electronics Co. to introduce a co-branded tablet in August that will carry Nook software and content. Huseby has been working to turn around the division, which has lost money for years as it struggles to compete with products from Apple Inc. and Amazon.com Inc.

Barnes & Noble posted a fourth-quarter net loss of $36.7 million, or 72 cents a share, compared with a deficit of $114.8 million, or $2.04, a year earlier. While the retail segment is profitable, generating $53 million in earnings before interest, taxes, depreciation and amortization last quarter, the Nook unit is not. It lost $56 million on an Ebitda basis, and those losses will continue this fiscal year, the company said.

The company has engaged Guggenheim Securities LLC as financial advisers and Cravath, Swaine & Moore LLP as legal counsel.

Takeover Offers

Huseby, who took over as CEO in January, joined the bookseller in 2012 as chief financial officer after working in the cable industry. Billionaire John Malone’s holding company Liberty Media Corp. offered to buy Barnes & Noble for about $1 billion in 2011, then dropped the bid in favor of buying $204 million in preferred shares. In April, Liberty said it would sell most of that stake.

Founder Leonard Riggio made his own run at the business last year, announcing his intention to break up the company by acquiring its stores and website, then abandoning the plan months later.

G Asset Management LLC proposed in February to acquire 51 percent of the company at $22 a share, valuing the total business at $1.32 billion. The firm also offered to buy 51 percent of the Nook business as an alternative deal. It said at the time it was confident that separating the business would unlock “substantial” shareholder value. In 2012, the firm also called for a Nook spinoff.