WASHINGTON — US lawmakers on Thursday sought to prevent Internet companies from censoring information overseas, hailing Google's threat to pull out of China as a turning point but saying it needed official support.

Members of Congress said they had new momentum to enact a bill that would prohibit US firms from storing users' personal information in countries that restrict the peaceful expression of political and religious views online.

"Google sent a thrill of encouragement through the hearts of millions of Chinese," Representative Chris Smith, the bill's chief sponsor, told a news conference. "It is a game-changer."

"But IT companies are not powerful enough to stand up to a repressive government like China. Without US government support, they are inevitably forced to be ever more complicit in the repressive governments' censorship and surveillance," said Smith, a Republican from New Jersey.

Under the bill, called the Global Online Freedom Act, the US government would list nations that restrict the Internet and prohibit US companies from storing personally identifiable information in those countries.

Companies would have to report to the State Department which terms countries are trying to filter out. China blocks citizens from accessing uncensored information on sensitive topics such as the 1989 Tiananmen Square crackdown, the Dalai Lama and the banned Falungong spiritual movement.

The bill would also prohibit companies from cooperating in jamming US government websites such as US-funded broadcasters Voice of America and Radio Free Asia.

Google said Tuesday said it would stop bowing to China's censors and could pull out of the China's lucrative online market of 360 million users after discovering Chinese attacks against dissidents' email accounts.

Smith has tried for years to bring the Global Online Freedom Act to the floor of the House of Representatives but it had met a lukewarm response from Internet companies including Google.

Smith declined to say if he expected other companies to lobby against the bill but said his concerns have focused on actions by four US companies -- Cisco, Google, Microsoft and Yahoo.

Yahoo came under intense criticism in 2005 for allegedly providing China with details leading to the email account of journalist Shi Tao, who was sentenced to 10 years in prison.