Watchmakers are turning to radio-controlled watches to beat out their Chinese and European counterparts, who tend to dominate the lower and higher ends of the market.

Citizen Watch Co. saw its sales for the watches, which automatically receive the correct time, jump to about 10 billion yen in fiscal 2003 from several tens of millions of yen in fiscal 2001.

"Thanks to radio-controlled watches, the average price of wristwatches has gone up by some 30 percent," said Osamu Yamada, director of Citizen.

Citizen plans to launch a sales offensive in China and other countries in the second half of fiscal 2004.

Radio-controlled wristwatches in Japan receive time signals from atomic clocks in Fukushima and Saga prefectures. The margin of error is said to be only 1 second in 100,000 years.

But thickness has been the main sticking point in their design, as they need a built-in antenna.

Citizen and two other watchmakers -- Casio Computer Co. and Seiko Watch Corp. -- are competing to market thinner and more fashionable versions.

Citizen will begin selling what it says is the world's thinnest radio-controlled analog watch -- at 6.8 millimeters -- under the high-end brand Exceed on Tuesday.

The watch, which has a glass face and leather band, costs 126,000 yen.

"We have thoroughly cut every part, and the watch is about 3 mm thinner than watches already on the market," a public relations official said.

Also Tuesday, Seiko will introduce three new models under its Dolce brand that are 7.9 mm thick and priced at 73,500 yen.

"We have produced fashionable wristwatches," Seiko President Shinji Hattori said. "With these, we will fully join the market."

Seiko used to order the internal mechanism from a German watchmaker, but it has begun jointly designing the mechanism with Seiko Epson Corp. Together, they have developed a mechanism that is between 4 mm and 5 mm thinner.

Casio began selling eight casual radio-controlled women's wristwatches at the end of May. They are priced at either 23,000 yen or 36,750 yen and are targeted at women in their 20s.

Casio sold 1.5 million radio-controlled wristwatches in fiscal 2003, up 50 percent over the year earlier.

Domestic watchmakers are busy trying to develop slim, dressy watches for women.

Higher revenues are expected from these, but further technological improvement is required to turn them into radio-controlled versions.