An executive at Sears and Kmart’s parent company said the distressed retailer remains “a viable business” even though it had warned regulators of “substantial doubt” that it could keep its doors open amid mounting losses.

Sears Holdings raised concerns about its ability to continue operations in its annual 10-K filing with the federal government.

The company also reported a $2.2 billion loss on sales of $22.1 billion for its fiscal year that ended Jan. 28, double its $1.1 billion loss the prior year.

But the company’s chief financial officer, Jason Hollar, wrote in a blog post Wednesday on Sears Holdings’ website that while “regulatory standards” required management to issue the “substantial doubt” statement the day before based on its dreary results last year, the company remained focused on turning itself around.

There are “actions we are taking to mitigate those risks,” and “we are a viable business that can meet its financial and other obligations for the foreseeable future,” Hollar wrote.

Even so, Sears Holdings’ regulatory filing rattled investors. The company’s stock plunged 12.3 percent to close at $7.98 on Wednesday.

Sears Holdings, based in the Chicago suburb of Hoffman Estates, is led by Chief Executive Edward Lampert, a hedge-fund manager who combined Sears and Kmart in 2005.

Both chains are iconic American brick-and-mortar retailers. Long before the Internet and online shopping, Sears’ product catalog was a staple in U.S. homes for decades, and Sears’ Kenmore appliances and Craftsman tools were household names.

But Sears Holdings has struggled with heavy losses for years as Sears and Kmart failed to keep pace with competition from the likes of discount chains such as Wal-Mart and Target and with changing consumer-spending habits that shifted toward e-commerce giants such as Amazon.com.

Sears Holdings has taken several steps to hang on, including shrinking the company to save costs.

It now has 1,430 stores nationwide, down 44 percent from the 2,548 it operated five years ago. The company employs 140,000 people.

Earlier this year, Sears Holdings also sold the Craftsman brand to Stanley Black & Decker for $900 million, and it has been reformulating its debts to gain liquidity.

The question is whether Sears and Kmart will be able to draw more shoppers. In its latest fiscal year, Sears’ comparable store sales — those of stores open at least a year — fell 9.3 percent from the prior year, and Kmart’s comparable sales fell 5.3 percent. Some analysts said the “substantial doubt” disclosure by Sears Holdings, which has lost $7.3 billion in the last five years, might indicate the retailer cannot be saved.