A letter signed by six prominent companies including Microsoft, was sent to legislative leaders on Thursday stating their support for gay marriage legislation in the state House and Senate.

As letters of support go, it's very short: "We write you today to show the support of our respective companies for SB 6239 and HB 2516 recognizing marriage equality for same-sex couples."

In addition to Microsoft, the letter was signed by officials from Vulcan, NIKE, RealNetworks, Group Health Cooperative, and Concur.

Microsoft created a flap in 2005 when said it was neutral on the initial gay-rights legislation. It failed in the Senate by one vote that year. After heavy criticism, the company later changed its position and endorsed the legislation, as well as subsequent bills, including domestic partnerships for same-sex couples.

The company last week said it was reviewing the legislation and had not decided whether to take a position.

Microsoft just issued a short statement explaining it's support:

"Microsoft is joining other Northwest employers Concur, Group Health Cooperative, Nike, RealNetworks and Vulcan Inc. in support of Washington State legislation recognizing marriage equality for same-sex couples. This position builds on our history of supporting corporate and public policies that promote inclusion and equality.

"Microsoft's greatest asset is a talented workforce as diverse as our customers. As other states recognize marriage equality, Washington's employers are at a disadvantage if we cannot offer a similar, equitable and inclusive environment to our talented employees, our top recruits and their families. This legislation would put Washington employers on equal footing with employers in the six other states that already recognize the committed relationships of same-sex couples. Passing the bill would be good for our business and for the state's economy."

You can read a longer explanation by Brad Smith, Microsoft's general counsel and executive vice president for legal and corporate affairs on the company blog.