James Martin/CNET

Mark Zuckerberg's FWD.us political action group has added a few more tech heavy hitters to its membership roster.

Microsoft co-founder Bill Gates, Microsoft CEO Steve Ballmer, Microsoft General Counsel Brad Smith, and entrepreneur and investor Sean Parker have all signed on in support of the Facebook CEO's group aimed at reforming immigration. AllThingsD earlier reported the news, and CNET confirmed the report with FWD.us.

"We've been excited by the momentum we continue to see as more members of the tech community contribute to the national debate to improve our economic future, and support the bipartisan policies that will boost economic growth and continue to grow the knowledge economy," FWD.us President Joe Green said in a statement.

Zuckerbergthrough an editorial in the Washington Post. FWD.us has vowed to work with members of Congress from both parties, the administration, and state and local officials to change how the U.S. approaches immigration. It plans to use online and offline advocacy tools to build support for policy changes.

The initial leaders of FWD.us, announced earlier in April, include: LinkedIn co-founder Reid Hoffman; Google Executive Chairman Eric Schmidt; Yahoo CEO Marissa Mayer; Dropbox CEO Drew Houston; angel investor Ron Conway; Chamath Palihapitiya of the Social+Capital Partnership VC fund; Joe Green, co-founder of the Causes Facebook app; Jim Breyer of the Accel Partners VC fund; Matt Cohler of the Benchmark VC fund; John Doerr and Mary Meeker of the Kleiner Perkins Caufield & Byers VC fund; Paul Graham, co-founder of the Y Combinator seed capital firm; PayPal co-founder Max Levchin; Aditya Agarwal, vice presient of engineering at Dropbox; and Ruchi Sanghvi, a former Facebook engineer who started a company later acquired by Dropbox.

Many technology companies have been pushing for changes to the immigration policy, seeking fixes that would let foreign engineers and scientists remain in the U.S. post-graduation. They have been hoping for prompt action for a pair of bills introduced this year that would ease the shortage of skilled workers, in part by expanding the H-1B visa program. However, changes have been stymied by the political mess known as comprehensive immigration reform.

Updated at 8:55 a.m. PT with comment from FWD.us.

Corrected at 10:25 a.m. PT to reflect which Brad Smith is joining FWD.us. The group is adding the Microsoft executive, not the Intuit CEO.