Clothing chain Pacific Sunwear of California Inc. reported late Thursday that its fourth-quarter loss widened as sales fell.

The teen retailer also forecast a weak first quarter, sending its shares down in aftermarket trading.

Pacific Sunwear posted a loss of $36.5 million, or 56 cents per share, for the quarter that ended Jan. 30, compared with a loss of $27 million, or 42 cents per share, for the period a year earlier. Excluding a valuation allowance, the company posted a loss of 26 cents per share.

Sales fell 17 percent to $293 million.

Analysts polled by Thomson Reuters, who typically exclude one-time items, were expecting the company to post a loss of 29 cents on revenue of $277.4 million.

CEO and President Gary H. Schoenfeld said he was pleased with Pacific Sunwear's progress, and it's young men's business could help lead a turnaround, but the company faces a tough period in its juniors' business.

For the full year, the company reported a loss of $70.3 million, or $1.07 per share, compared with a loss of $63.8 million, or 76 cents per share, the year before. Excluding one-time items, the company posted a loss of 78 cents per share for the year.

Sales fell 18 percent to $1.03 billion.

The company expects to report a loss of 50 cents to 60 cents per share for the current quarter, or 32 cents to 38 cents per share on an adjusted basis — well below analyst expectations of a loss of 15 cents per share.

Shares of Pacific Sunwear fell 87 cents, roughly 15 percent, to $4.90 after hours. They closed Thursday at $5.75, up 4 cents.