Three of Japan's largest electronics companies plan to work together on developing advanced semiconductor technology.

Toshiba, NEC Electronics and Sony will combine their resources to work on process technologies for 45-nanometer generation chips. A nanometer is a millionth of a millimeter and the measurement refers to the size of the smallest feature on a chip's surface.

As features shrink, chips can become smaller, more powerful and more energy efficient - all attractive features, particularly for chips for portable electronics devices. Most advanced chips are made today on 90-nm production lines and some companies, like Intel, have recently started 65-nm production lines.

"We will work on fundamental process technology," said Sophie Yamamoto, a spokeswoman for NEC. "We're looking at 45-nm for digital audio-visual and mobile devices because for them, high-speed and low power consumption are important."

That the three companies will work together don't come as a surprise. Toshiba and Sony agreed two years ago to work together on 45-nm chip technology, and Toshiba made a similar agreement with NEC in November. It said at that time that there was a good chance the three parties would come together in a single project.

Under the plan, engineers from NEC Electronics will join around 150 Sony and Toshiba technicians already engaged in 45-nm work at Toshiba's Advanced Microelectronics Center in Yokohama.

The companies haven't disclosed when they hope to complete development but the agreement is valid until September 2007.

The agreement comes as semiconductor companies are increasingly looking to work together to offset the high costs of developing ever-more advanced chip technology and production lines.

Toshiba and Sony have a similar development deal with IBM covering 32-nm technology for future chips.

In January, Toshiba and two other local chip makers, Hitachi and Renesas Technology, began exploring the feasibility of a joint venture that could handle future semiconductor production for them. The proposed plant would produce system LSI (large-scale integration) chips based on 65-nanometer or finer technology, they said.