AFP - US authorities announced plans Monday to revamp antitrust enforcement with a new policy that calls for "aggressively pursuing" cases of monopoly abuse.
  
The Justice Department said it was withdrawing, effective immediately, guidelines on antitrust enforcement issued in September 2008 under the administration of president George W. Bush.
  
"Consumers, businesses, courts and antitrust practitioners should not rely on (the prior guidelines) as Department of Justice antitrust enforcement policy," according to a department statement.
  
The scrapping of the prior guidance "is a shift in philosophy and the clearest way to let everyone know that the Antitrust Division will be aggressively pursuing cases where monopolists try to use their dominance in the marketplace to stifle competition and harm consumers," said the agency's antitrust chief Christine Varney.
  
"The Division will return to tried-and-true case law and Supreme Court precedent in enforcing the antitrust laws."
  
The announcement marks a shift by the administration of President Barack Obama on questions of monopoly abuse, which could affect key US technology giants.
  
Google, the Internet search giant, is coming under increasing scrutiny of antitrust regulators.
  
European regulators meanwhile are taking a tough stand on American computer chip maker Intel.
  
The Bush administration settled an antitrust case against US software giant Microsoft brought by the administration of Bill Clinton.
  
Varney said that the prior guidelines "advocated hesitancy in the face of potential abuses by monopoly firms" and were based on the notion that monopoly markets are self-correcting.
  
She added that the Bush policy "raised too many hurdles to government antitrust enforcement and favored extreme caution" in government action to prevent abuse of a monopoly.
  
"The recent developments in the marketplace should make it clear that we can no longer rely upon the marketplace alone to ensure that competition and consumers will be protected," she said.
  
Mark Thoma, a University of Oregon economist, called the move "a welcome change."
  
He added that "the financial crisis has caused me to realize how much political power comes with dominance in the marketplace, and that is another reason to take a more aggressive approach to antitrust enforcement."
  
Some analysts said the administration was setting its sights on Google.
  
Google has acknowledged that it has been contacted by the US Federal Trade Commission regarding potential legal conflicts caused by chief executive Eric Schmidt and director Arthur Levinson being on the Apple board.
  
US regulators last year approved Google's purchase of online advertising tracking firm DoubleClick but stymied a planned advertising alliance with Yahoo!.
  
Danny Sullivan at Search Engine Land said the main reason for targeting Google could be its dominance of Internet search and the related advertising market.
  
"Google potentially controls too many points along the Internet advertising ecosystem," he said.