(Adds details; updates shares)
Aug 21 (Reuters) - Sears Holdings Corp reported its ninth straight quarterly loss as sales continued to fall and the retailer said it might close more stores than planned this year.
Shares of the company, which owns Sears department stores and the Kmart discount chain, fell as much as 7 percent in opening trading.
Sears, controlled by hedge fund manager Eddie Lampert, has been closing stores, cutting inventory and selling property and assets to try to turn its business around after nearly a decade of falling sales.
The company's revenue fell 9.7 percent in the second quarter, reflecting the impact of the separation of its Lands' End clothing business and store closures.
Same-store sales fell 1.7 percent at Kmart stores. Sears had 2,302 stores in the United States as of Aug. 2, of which 1,077 were Kmarts.
Lampert said Sears was making progress in its turnaround efforts. "In the next 6-12 months, we intend to work with our lenders and others to evaluate our capital structure with a goal of achieving more long term flexibility," he said on a recorded call on Thursday.
Sears said it continued to explore with Bank of America Merrill Lynch a sale of its 51 percent stake in Sears Canada or the sale of the entire Canadian company.
Sears Canada, which reported its ninth loss in 14 quarters on Wednesday, had a market value of about $1.5 billion on the day.
Sears is also trying to sell its auto-service center business.
The company, once the largest U.S. retailer by revenue, has seen sales fall since 2005. Stiff competition from Target Corp , Wal-Mart Stores Inc and Home Depot Inc and online retailers such as Amazon.com Inc has eaten into the company's business.
Sears, which has closed about 300 stores since 2010, said it might close more than the 130 stores it had earlier planned to shut this year.
The loss attributable to the company's shareholders widened to $573 million, or $5.39 per share, in the second quarter ended Aug. 2 from $194 million, or $1.83 per share, a year earlier.
Revenue declined to $8.01 billion from $8.87 billion.
Excluding items, Sears posted a loss of $3.00 per share, according to Thomson Reuters I/B/E/S.
Analysts on average had expected a loss of $2.63 per share and revenue of $8.13 billion.
Sears shares were down 5.2 percent at $34.05 in early trading on the Nasdaq.
Up to Wednesday's close, the stock had fallen 5.8 percent this year. (Reporting by Shailaja Sharma in Bangalore; Editing by Kirti Pandey)