Toshiba Plans New Color Notebook PC : Technology: The product is an attempt to gain back market share lost to rivals.

Hoping to revive its faltering computer business, Toshiba America Information Systems today plans to unveil a lightweight notebook computer with an advanced color display said to match the quality of desktop machines.

The T4400SXC computer will be the flagship model in Toshiba’s effort to remain the leader in the $1.4-billion portable computer market. Toshiba America, an Irvine-based subsidiary of Japan’s Toshiba Corp., is unveiling the model at the Comdex computer trade show in Chicago.

Battered by dozens of new competitors in the fast-growing market, Toshiba’s share of U.S. portable computer sales plunged from 20% in 1990 to 14% last year, according to International Data Corp., a Framingham, Mass., market researcher. Analysts attribute the decline largely to a series of missteps the company made in early 1991.

“Toshiba was used to being king of the hill when portable computers were specialty products,” said Andrew Seybold, editor of the Outlook on Personal Computing newsletter in Boulder Creek, Calif. “Now they are standard offerings, and desktop vendors will continue to take market share.”

Although Toshiba is still the No. 1 seller of portable computers, rivals such as International Business Machines, Apple Computer and AST Research in Irvine have cut into its sales. The fierce competition led to a price war that resulted in notebook computer prices plummeting 40% last year.

“For (Toshiba), this color computer is a very important product and one that could help them keep their leadership role,” said Tim Bajarin, vice president of Creative Strategies, a Santa Clara market research firm.

Michael Winkler, general manager of Toshiba’s computer division, acknowledged that the company’s sales were flat last year. He declined to give further details.

But Winkler, who took over as general manager in October, contended that the company has bounced back the past six months, revamping its engineering department and introducing a raft of new models that have won plaudits from the industry press.

“There was a brief period where we missed our mark and lost image and market share,” he said. “But we’re still on top.”

The division has cut costs by laying off about 9% of its 1,650 employees.

Analysts said Winkler has played an important role in helping the company better position its products in the market and fend off competition.