A pastor who threatened a national boycott against Microsoft and other major corporations for endorsing a gay rights bill urged supporters Tuesday to buy up the companies' stock and dump it to drive prices down.

Rev. Ken Hutcherson, pastor of Antioch Bible Church in the Seattle suburb of Redmond, said the stock-dumping plan had been part of his strategy all along.

"You got to find out how you affect a company," Hutcherson said, conceding that it would be hard to get people to shun products from companies that dominate the marketplace as Microsoft and Boeing do.

He wants supporters to buy one or two shares over the next few months, then sell them May 1.

Companies including Microsoft Corp., Boeing Co., Hewlett Packard Co. and Nike Inc. signed a letter earlier this month urging passage of the gay rights measure, which would add "sexual orientation" to a state law that already bans discrimination based on race, gender, age, disability, religion and marital status.

Hewlett Packard and Boeing released statements Tuesday reaffirming their support for the measure. None of the other companies immediately returned calls from The Associated Press.

Experts said the pastor's plan has no chance of hurting the stock price of a company such as Microsoft.

Hans Olsen, chief investment officer at Bingham Legg Advisers, said few investors would gamble their money on a political statement, especially large investors, such as those who hold major blocks of shares in mutual funds.

"The big guys, they won't touch that with somebody's else 10-foot pole, let alone their own," Olsen said.

A Senate committee approved the bill Tuesday, meaning it could come to a vote on the Senate floor by the end of the week. The House passed it last week.

Microsoft's endorsement of the bill comes a year after the company was denounced for quietly dropping its support.

Hutcherson was at the middle of the Microsoft controversy last year, claiming he pressured the company into withdrawing its support by threatening a boycott.

The company, under fire from gay activists across the country, insisted it had decided to take a neutral stance to focus on other issues.