Steve Ballmer, the company's chief executive, announced the reversal in an e-mail message sent to 35,000 Microsoft employees in the United States. ''After looking at the question from all sides, I've concluded that diversity in the workplace is such an important issue for our business that it should be included in our legislative agenda,'' he said.

''I respect that there will be different viewpoints. But as CEO, I am doing what I believe is right for our company as a whole.''

Long known for its strong internal policies protecting gay employees from discrimination and offering them benefits, Microsoft sparked an uproar last month when officials decided to take a ''neutral'' stance on the anti-discrimination bill this year, after supporting it for the two previous years.

Critics, including employees who said they were told until recently that Microsoft would support the bill, insisted the decision was made under pressure from a local evangelical Christian preacher who threatened to boycott the company if it supported the legislation this year, an accusation the company has denied.

The bill, which would have extended protections against discrimination in employment, housing and other areas to gay men and lesbians, failed by one vote on April 21. But it is automatically up for a new vote next year because bills introduced in the Washington Legislature are active for two years even if they are voted down the first time.

After the defeat, Ballmer sent an e-mail message to company employees, defending the decision to withdraw support. In that note, Ballmer said that he and Microsoft's founder, Bill Gates, both personally supported the anti-discrimination measure but felt the company should focus its legislative efforts on measures that had a more direct connection to their business.

In Friday's message, Ballmer seemed to suggest that ''input'' from employees helped persuade Microsoft officials to renew their backing of the measure. More than 1,500 employees had signed an internal petition demanding the company support the bill, and scores had written in protest to Ballmer and Gates.

A Microsoft executive said that after Microsoft's turnaround on the bill was widely publicized and prompted internal company uproar, a group of senior officials met and decided to change the company's position because of the internal pressure from employees.

''This issue got attention at the highest levels of the company in a way it didn't before,'' the executive said.