Women's apparel retailer Wet Seal reported a bigger-than-expected quarterly loss, hurt by a double-digit fall in comparable-store sales.

Wet Seal shares fell 20 percent in extended trading after the company also forecast a bigger-than-expected loss for the current quarter.

The company said it expected a current-quarter loss of 9 cents to 12 cents per share, including a 2 cents per share loss from the Arden B business.

Analysts on average were expecting a loss of 4 cents per share, according to Thomson Reuters I/B/E/S.

Wet Seal posted a net loss of $21.8 million, or 26 cents per share, for the first quarter ended May 3, compared with net income of $3.11 million, or 3 cents per share, a year earlier.

Net sales fell 16.8 percent to $116.7 million, while comparable-store sales decreased 16.9 percent.

Analysts had expected a loss of 18 cents per share.

In April, Wet Seal said it would exit its clothing brand Arden B and convert its 54 Arden B stores to Wet Seal stores.

Wet Seal shares closed at $1.01 on the Nasdaq on Tuesday.