American Apparel Inc needs more time to report second quarter results and final results for the first quarter due to the resignation of its auditor, the company stated in a regulatory filing on Tuesday.

But the Los Angeles clothing manufacturer and retailer, known for its T-shirts, skin-tight leggings and mesh body suits, said it expects to report a net loss for the second quarter due to rising manufacturing costs and operating expenses.

Net sales are also are expected to decrease compared with the same period last year. The company said it’s expecting negative same-store sales for the second quarter, but is expecting an increase in its wholesale business.

American Apparel said in a Securities and Exchange Commission filing that its new auditor, Marcum LLP, needs sufficient time to review financial statements for the quarters ended June 30, 2010 and May 31, 2010 before it can report final results.

Deloitte & Touche LLP resigned on July 22 as American Apparel’s auditor, stating that the company’s 2009 financial results may not be reliable. Tuesday’s filing said American Apparel is working to provide Deloitte with additional information so the accounting firm can assess the reliability of its 2009 information.

Executives at American Apparel didn’t immediately return requests seeking comment.

Meanwhile, a New York law firm announced Tuesday that it’s launching an investigation into possible violation of state and federal securities law by American Apparel. The firm, Abraham Fruchter & Twersky LLP, handles insider trading, shareholder derivative and securities fraud actions.

Shares were down 11 cents, or about 4 percent, to $1.44 in after hours trading on the New York Stock Exchange.