P. M. BRIEFING : U.S., Japan Chip In for Progress

TOKYO — AT&T; Microelectronics, a unit of American Telephone & Telegraph Co., and Japan’s NEC Corp. today agreed to cooperate in developing and marketing a wide range of semiconductor products.

The five-year deal calls for cooperation in developing semi-custom microchips and manufacturing four-bit microcontrollers, a chip that controls logical functions in a computer, and stepped-up activity to promote the use of AT&T; chips in NEC’s systems products.

“The agreement will benefit the customers of both companies through strengthening product lines and technical capabilities,” William Warwick, president of AT&T; Microelectronics told reporters.

The deal is the latest between American and Japanese microchip firms, which aim to share technology and development costs and reduce trade friction between the two economic powers.