A racial discrimination lawsuit filed last year by a former employee against the Microsoft Corp. was expanded on Wednesday to include six additional plaintiffs who allege that they were overlooked for promotions, pay raises and other advancements because of their race.

The lawsuit, filed last June on behalf of former Microsoft salesman Rahn Jackson, was amended into a US$5 billion class-action suit in US District Court in Washington, according to attorneys for the plaintiffs.

The seven African-American plaintiffs, all of whom are current or former Microsoft employees, also allege in the suit that their race played a significant role in wrongful terminations and retaliation by the company after they complained about their treatment.

"Microsoft has discriminated against African-American employees who made valuable contributions to the company, but were not treated with the same dignity, respect and compensation as their white counterparts," said plaintiff's attorney Willie Gary in a statement on Wednesday. "There are glass ceilings and glass walls in place for African-Americans at Microsoft. We are stunned and disappointed in their treatment of black employees."

MS denial Deborah Willingham, Microsoft's vice president of human resources, said in a statement that executives at the company haven't reviewed the amended lawsuit yet and wouldn't comment directly on the matter as a result.

But, Willingham said, Microsoft "has a zero-tolerance policy toward discrimination in the workplace" and takes "any allegations of discrimination very seriously." The software vendor "is 100 per cent committed to diversity" and "works actively to recruit, train and promote minority and women employees," she said.

Minority massing Willingham added that Microsoft's minority workforce has actually grown nearly twice as fast as the company's overall domestic workforce during the past three years.

However, Gary claimed that Microsoft's own employment statistics provide evidence that the company does little to hire or retain African Americans.

In 1999, Microsoft had 21,429 workers, of which 2.6 per cent, or 553, were African-American, according to the figures provided by Gary. Of the firm's 5,155 managers, 1.6 per cent, or 83, were African-American, according to the figures.

Jackson again The original discrimination suit filed on behalf of Rahn Jackson is pending before US District Judge Thomas Penfield Jackson in Washington, the same judge who ruled against Microsoft last year in a renowned federal antitrust case.

The amended case will be opened as a class-action suit for current and former African-American employees of the company since 1992.

Last July, the US Commission on the Advancement of Women and Minorities in Science, Engineering and Technology blasted what it said was a poor diversity record in IT hiring and recommended steps to train and bring in more female, minority and disabled workers