AFP - The operator of Japan's recession-busting clothing chain Uniqlo said Friday its quarterly profit surged on strong sales of winter underwear, upgrading its full-year outlook.

Fast Retailing said its net profit jumped 57.2 percent from a year earlier to 34.9 billion yen (374 million dollars) in the three months to November.

Operating profit surged 49.1 percent to 61.1 billion yen in the first quarter of the group's business year, on revenue of 263.5 billion yen, up 39.8 percent year-on-year, the company said.

The strong performance was mainly due to brisk sales of autumn and winter lines, led by Uniqlo's "HeatTech" innerwear.

"Sales of HeatTech have remained strong as we considerably raised the quantity of the products," Toshihisa Tokunaga, a senior official of the firm, said, adding that some of the items sold out in December.

Tokunaga also attributed the firm's robust performance to an expansion in its operations across Asia as well as Europe and the United States, despite tough competition with its foreign rivals such as Gap, Zara and H&M.

Sales at Uniqlo's new flagship Paris store, which opened in September, have been better than expected, he said.

Fast Retailing revised upward its forecast for the full business year to August 2010, predicting a net profit of 67.5 billion yen, against an earlier estimate of 62 billion yen.

It anticipates a record operating profit of 130.5 billion yen on revenue of 820 billion yen, which would also be an all-time best.

The casual clothing empire, founded by billionaire Tadashi Yanai, is seen as a rare success story in Japan's retail sector, which is struggling in the face of weak consumer spending and renewed deflation.