Nearly three months after announcing that IBM was selling its half of Dominion Semiconductor LLC to Toshiba Corp., the Manassas chip plant announced a joint venture to develop high-density gigabit flash memory chips, which will result in at least 250 new jobs.

Dominion Semiconductor will manufacture the flash memory chips for the new joint venture company to be formed early next year by Toshiba and SanDisk Corp. The production of flash chips will make up about 50 percent of Dominion's total manufacturing, company officials said.

The official production of the new chips at the plant will begin in 2001. In the meantime, Dominion will be preparing for the production by "choosing and installing the tools, getting the product qualified and running," said Mark Holcomb, spokesman for Dominion.

The new chips will be about four times as dense as the D-RAM chips, which are the most common type of computer memory, the company now makes. Flash memory chips, which are often used in digital cameras and cellular telephones, allow computers and other devices to hold information even when they're turned off.

By 2002, the flash memory production of the joint venture is projected to have annual sales of$1 billion.

Dominion will make a total investment of about $2 billion for the new manufacturing. That cost includes the building, which is already completed, the new equipment and new employees.

"We view this as the first dividend of Toshiba buying out IBM," said Holcomb. "It's good news."

In July, Toshiba bought International Business Machine Corp.'s portion of the Manassas chip-making venture.

Dominion has about 900 employees and has the space for as many as 1,200.