Google must do more to allay concerns that it is blocking competitors in web search results, the EU's antitrust chief said on Wednesday, after rivals criticised concessions it has offered as being inadequate.
The world's most popular search engine submitted proposed concessions to the European Commission in April to end a three-year investigation and responded on Wednesday that its proposal "clearly addresses" areas of concern.
Google, which has a market share of over 80 percent in Europe's Internet search market according to research firm comScore, could face a fine as much as $5 billion if it does not resolve the issue.
"I concluded that the proposals that Google sent to us are not enough to overcome our concerns," European Competition Commissioner Joaquin Almunia told a news conference on Wednesday, adding that he has asked Google to present better proposals.
Almunia, who has previously said he hopes to decide on the case by the end of the year, did not say whether he had set a deadline for the company to reply.
Google spokesman Al Verney said the company would continue to work with the EU competition authority. "Our proposal to the European Commission clearly addresses the four areas of concern," he said.
The company has offered to mark out its own products in Internet search results, provide links to at least three rival sites and make it easier for advertisers to move to rival platforms.
The EU competition regulator has sought feedback from Google's rivals and third parties and a number of them have said any concessions would only reinforce Google's dominance.
Reacting to Almunia's comments, lobbying group ICOMP called on the Commission to penalize Google if it does not come up with a better offer.
"The Commission must set a tight deadline failing which the commitments procedure should come to an end," ICOMP lawyer David Wood said in a statement.
Another lobbying group FairSearch, whose members include complainants Microsoft, online travel agency Expedia , British price comparison site Foundem and France's Twenga, said Google's offer was "highly unlikely" to boost competition.