White House officials raised concerns on Saturday about online piracy legislation in the works in Congress that top technology companies have decried as heavy-handed, saying a lighter touch would be better.

In a statement, three advisers to President Barack Obama said they believed the proposed Stop Online Piracy Act (SOPA) and other bills could make businesses on the Internet vulnerable to litigation and harm legal activity and free speech.

"Any effort to combat online piracy must guard against the risk of online censorship of lawful activity and must not inhibit innovation by our dynamic businesses large and small," said the officials, including White House cyber-security czar Howard Schmidt.

The House of Representatives' SOPA bill aims to crack down on foreign websites selling pirated US movies, music or other counterfeit goods by allowing private parties to target the websites' advertisers and payment providers.

It has put Internet giants, consumer groups and free speech advocates in opposition to US copyright industries, including Hollywood studios and music labels, that have long argued for tougher protection.

The search engine Google Inc told Congress in November the bill went too far and could depress investment. Along with leading online firms Yahoo!, Facebook, Twitter and eBay, it ran advertisements in major newspapers urging lawmakers to rethink their approach.

Proponents of the legislation argue that current US laws leave few options for copyright holders whose products end up on foreign websites.

Lamar Smith, a Texas Republican who chairs the House judiciary committee, said the bill went after those who steal US technology and products and distribute them illegally.

"It is not censorship to enforce the law against foreign thieves," Smith said on Saturday, estimating that intellectual property industries provide 19 million high-paying US jobs and account for more than 60 percent of American exports.

"Congress cannot stand by and do nothing while some of America's most profitable and productive industries are under attack," he said in a statement responding to the White House.

Smith, in an interview with Reuters on Thursday, vowed to press ahead with the bill.

'WORST OFFENDERS'

Under the SOPA bill, if a judge agrees that websites offer material that violates US copyright laws, Internet service providers could be required to block access to foreign sites and US online advertising networks could be required to stop ads and search engines barred from directly linking to them.

The US Chamber of Commerce said on Saturday it strongly supported the House legislation as well as the "Protect IP Act" in the Senate, calling both "narrowly targeted bills designed to target the worst of the worst offenders."

"Given the broad consensus that this issue needs to be addressed, it is time to come together and adopt strong legislation that ends the ability of foreign criminals to prey on innocent consumers and steal American jobs," it said.

Schmidt and the other advisers said the Obama administration was ready to work with lawmakers on a narrower, more targeted approach to online piracy to ensure that legitimate businesses - including start-up firms - would not be harmed.

They also said online firms and Internet providers should adopt voluntary standards to clamp down on piracy, an approach that Republicans in Congress and many companies have said lacks the teeth to have an impact.

Saturday's statement did not make clear whether Obama would veto the piracy legislation if it reaches his desk, something the White House would likely spell out more formally ahead of a vote in Congress.

Sherwin Siy, deputy legal director of the consumer rights group Public Knowledge, called on lawmakers to set aside the existing bills and get to work on a new "consensus bill" responding to the White House concerns.

"The messages being sent by the public in opposition to this bill are finally getting through to Washington," Siy said.