NEW YORK (CNNMoney) -- After years of huge losses and store closings, the future is officially in doubt for Sears and Kmart.
Sears Holdings, the holding company for the two iconic retail brands, warned investors late Tuesday that it can't promise it will stay in business.
It included the language in its annual report while insisting it might still turn things around.
"Our historical operating results indicate substantial doubt exists related to the company's ability to continue as a going concern," said the statement.
Sears Holdings said it can't be sure it can raise the cash it needs through loans and debt financing. The company owes $4.2 billion, up from about $3 billion a year ago.
The company lost $2.2 billion in the fiscal year ending in January and has not turned an annual profit since 2010. Its losses since then total $10.4 billion.
Sears Holdings said its ability to sell assets, such as stores and store leases, could be limited because it needs those assets to pay for pension plans. In January, Sears sold its Craftsman brand of tools to Stanley Black & Decker. It is looking to sell Kenmore appliances and Diehard auto parts.
Sears Holdings has been in trouble almost since the 2005 merger that joined the two department store brands.
At the start of 2006, it had 3,400 U.S. stores and 370 more in Canada that it has since sold. By the end of this January, it had only 1,400 stores left, all in the United States. The company still has 140,000 employees, but that too is down sharply from the 355,000 it had in 2006.
Even that doesn't tell the full picture of the decline.
Sears was once the nation's largest retailer and business employer, both the Walmart and Amazon of its time. Its groundbreaking catalog business was how many Americans learned to shop from home for a large variety of items they wanted.
And it developed an extensive store network that helped furnish homes as Americans moved to the suburbs after World War II. It also caused trouble for small, locally owned shops.
The company at one time grew to include not just the retail business but a bank, a brokerage, a real estate company and what was then the world's tallest building, the Sears Tower, for its Chicago headquarters.
But Sears began to suffer from competition from low-price competitors such as Walmart, and big-box stores such as Home Depot. It lost its place in the Dow Jones index of the nation's most important companies in 1999.
Then came growing competition from Amazon and other online retailers. Analysts said Sears Holdings did little to invest in either the Sears or Kmart brand, instead trying to cut its way back to profitability by trimming advertising and closing stores.
It announced plans to close 150 more stores in January, and its stock hit a post-merger low in February. Then the stock rebounded when the company announced a deal with creditors to borrow $140 million more and cut at least $1 billion in operating costs a year, along with reducing its debt and pension obligations by $1.5 billion.
The "going concern" warning sent shares down 5% in pre-market trading Wednesday.