Since American Apparel Inc. lost about 2,000 workers to an immigration sweep two years ago, it’s been difficult for the clothing maker and retailer to get the right products in the right stores at the right time.

But as the downtown L.A. company has started renovating stores and improving its inventory and distribution systems, it’s sales have steadily increased – and investors have taken notice.

The company posted a 21 percent sales increase in August compared with the same month last year, helping drive American Apparel stock to a new 52-week high. Shares ticked up 17 percent last week and closed at $1.60, making it the top gainer on the LABJ Stock Index for the week ended Sept. 26 (see page 24).

The stock has nearly doubled in value in just two months, hitting a 52-week high and approaching prices not seen since late 2010.

Sales through the first six months of the year were up 13 percent over the first half of 2011, according to the company’s most recent quarterly filing. Since then, it has announced solid sales growth each month, led by double-digit gains in online and same-store sales.

Dov Charney, American Apparel’s chief executive, told the Business Journal that the gains are the result of store renovations and inventory system improvements.

“We’re getting the product assortment in each store optimized; we’re renovating stores; we’re trying to ship to our stores more accurately and get product to stores before we run out of stock,” he said.

Managing inventory was a challenge for the company after the 2010 immigration sweep. Charney said the American Apparel factory was still reeling from that loss last year.

With those problems being addressed, he said that he expects sales to continue to grow. The company is only about halfway through the process of renovating stores and improving inventory systems.

“Yes, there has been some positive sales trend, but there is still room for improvement,” he said. “I anticipate we can continue this trend for 36 months.”

Still, the company needs to address other issues, mainly financial. It had a close brush with bankruptcy last year and is still losing money, thanks in part to payments on $96 million in high-interest loans. In the quarter ended June 30, the company paid $10 million in interest and posted a loss of $16 million. Charney said he hopes to refinance the company’s debt, now carrying an interest rate of 18 percent, within a year.