Foothill Ranch-based teen retailer Wet Seal Inc.’s sales for stores open at least a year fell in March, missing Wall Street analyst expectations.

The retailer reported a 7.8% decline in same-stores sales.

Analysts had expected a 6% decrease.

Wet seal operates its 469-store namesake chain for teen girls and an 84-store Arden B chain for young women. Both divisions reported March same-store declines.

Wet Seal Chief Executive Susan McGalla said in a statement that the company’s March performance was in line with the company’s expectations.

Arden B took the biggest hit last month, with same-store sales falling 8.6% during the month compared to a year earlier as the chain struggled with its tops business.

“We remain focused on maintaining a strong dress business while building strength in the bottoms category,” McGalla said. “In addition, we are working to improve our tops assortment, which we expect will provide more compelling outfitting solutions for the customer.”

The Wet Seal chain’s same-store sales fell 7.6% last month compared with a year-earlier period on weak performance in the tops and jewelry categories. Meanwhile, the chain said it saw successes in its bottoms, dresses and shoe businesses.