K-Swiss Inc. shares dropped 19 percent Thursday after the athletic-shoe maker reported a smaller-than-expected first quarter loss but warned that an overseas plant closure would hurt sales this year.

The Westlake Village company reported a net loss of $4.7 million (-13 cents a share), compared with a net loss of $1.1 million (-3 cents) a year earlier. Revenue fell 11 percent to $65.9 million, with sales weaker both in the United States and internationally.

Analysts surveyed by Thomson Reuters on average expected a per-share loss of 14 cents on revenue of $68.6 million.

One of the company’s three overseas contract manufacturers in Thailand closed last month. K-Swiss said that it is searching for alternative providers, but could not say when and how much capacity will be replaced. As a result, the company expects a 5 percent to 10 percent drop in full-year revenue because it will be unable to fill orders for about 700,000 pairs of shoes, mostly for its Latin American and European markets.

“While the unexpected short-term loss of capacity in Thailand is disappointing and has cost us some important business, we are continuing to make inroads in running and tennis shoes with product innovations and marketing efforts,” said Chairman Steven Nichols in a statement.

Shares closed down $2.29, or 19 percent, to $9.75 on the Nasdaq.