Gap saw like-for-like sales fall back 11% in July.
Gap's net sales were down 5% to $998 million (£517.5m) for the four weeks ended August 2.
Gap's international comparable sales, which includes its UK stores, fell by 9% over the period against an 11% uplift in July 2007.
Gap chief financial officer Sabrina Simmons said: "In July, we focused on clearing through remaining summer product and preparing our stores for fall deliveries. We're pleased that we delivered merchandise margins significantly above last year."
Gap's second quarter sales for the 13 weeks ended August 2 also fell 5% to $3.5 billion (£1.8bn), with like-for-like sales down 10%. International comparable sales in the second quarter were down 6%.