A hearing to debate and amend the controversial Stop Online Piracy Act (SOPA) in the U.S. House of Representatives has been delayed, likely until early next year.

The House Judiciary Committee had planned to continue with a third day of markup hearings on SOPA on Wednesday, if the House was still in session. But the House leadership plans now to break for the holidays before Wednesday morning, a spokeswoman for the committee said.

The continued markup has been "postponed until the House is again in session," the spokeswoman said Tuesday. "At this point, we expect that to be early next year."

The Judiciary Committee held a 10-hour bill markup session last Thursday, then met again for a short time Friday before being interrupted by votes on the House floor. Representative Lamar Smith, a Texas Republican and committee chairman, had first suggested the next markup would be after the holidays, then scheduled a hearing for Wednesday if the House was still in session.

So far, the committee has voted down about 20 amendments designed to address concerns by Web-based companies, Web security experts and digital rights groups.

SOPA would allow the U.S. Department of Justice and copyright holders to seek court orders blocking payment processors and online advertising networks from doing business with foreign sites accused of infringing copyright.

DOJ-requested court orders could also bar search engines from linking to the allegedly infringing sites, require domain name registrars to stop resolving queries that direct traffic to those sites, and require Internet service providers to block subscriber access to sites accused of infringing.

Also on Tuesday, the White House Office of U.S. Trade Representative released an update to its list of "notorious" markets for the sale of pirated and counterfeit goods. The list includes 18 websites, including BitTorrent indexing sites and cyberlockers.

The list shows the need for Congress to pass SOPA or the similar Protect IP Act (PIPA), the U.S. Chamber of Commerce said. Educational efforts to warn the public about the so-called rogue websites can take years, the Chamber said.

"That is why we need rogue sites legislation now -- to give our courts the ability to cut off foreign criminals from the U.S. marketplace," the Chamber said in a statement. The two bills "provide reasonable and effective ways" to enforce copyright law.

Earlier this week, the Messaging Anti-Abuse Working Group (MAAWG), an international nonprofit group fighting online phishing, botnets and fraud, released a letter to Congress about concerns members have about Web filtering techniques authorized in SOPA and PIPA.

The bills could "unintentionally" increase Web security risks, the group said in the letter.

"The filtering technologies outlined in these bills also would significantly impact the currently reliable messaging processes that are depended on worldwide and would require drastic architectural changes to existing network operations," MAAWG added. "These bills, if passed in their present form, will make it exceedingly difficult -- if not arguably impossible -- to protect the Internet community from ongoing attacks on critical infrastructure, to block spam, child pornography and malware, and to prevent phishing attacks against individuals and commercial enterprises."

Grant Gross covers technology and telecom policy in the U.S. government for The IDG News Service. Follow Grant on Twitter at GrantGross. Grant's e-mail address is grant_gross@idg.com.