Same-store sales at Gap Inc tumbled 14% in May as shoppers shunned its Gap, Banana Republic and Old Navy stores.

Net sales for the four weeks to 31 May fell 8% to $1.09bn from $1.19bn.

By division, comparable store sales fell 7% at Gap North America, were down 5% at Banana Republic North America, and plunged 25% at Old Navy North America. International same-store sales were flat.

"Old Navy continues to be our biggest challenge," said Sabrina Simmons, chief financial officer of Gap Inc.

"As we have stated, we are working to rebalance Old Navy's mix of fashion and seasonal basic items, and expect to see improvements in the assortments by late fall."

She also noted that merchandise margins in May were significantly above last year.

Year-to-date sales are down 6% at $4.47bn and comparable store sales are down 12%.