NEW YORK — Nantucket Industries Inc. posted a loss of $565,469 in the third quarter ended Nov. 27, stung by continuing cost variances at its Puerto Rico plant.

The loss compares with a profit of $451,060, or 18 cents a share, a year earlier. Sales in the latest quarter rose 1.6 percent to $13.4 million from $13.2 million.

In the nine months, the manufacturer of men’s and women’s underwear and socks lost $972,054 against a profit of $980,528, or 40 cents a share. Sales slid 7.5 percent to $33.8 million from $36.5 million.

Nantucket acquired the Puerto Rico plant in February 1993 and in April discovered an inventory loss of $1.8 million involving unfinished goods. Nantucket filed suit against Phoenix Associates, the former owners of the plant, seeking $4 million in compensatory damages for fraud.

High legal and other professional fees contributed to the losses in the quarter and the nine months, and Nantucket expects to continue to incur substantial legal and other professional expenses as it attempts to recover losses related to its Puerto Rico plant.