The inquiry, which began in November 2010, centers on whether Google has abused its dominant position as the most widely used search engine in Europe, and in particular on whether Google has favored its own products and services over those of rivals. In October, the union agreed to a tentative deal that would have required Google to make concessions to provide rivals with greater visibility on Web search queries.
Speaking to Spanish radio, JoaquÃn Almunia, the unionâ€™s competition commissioner, said Googleâ€™s â€œlatest proposals are not acceptable.â€ He added that time was running out for the company to offer further concessions that would allay the authoritiesâ€™ concerns about potential anticompetitive practices. He did not say which of Googleâ€™s concessions had not gone far enough.
Although Mr. Almuniaâ€™s comments stopped short of a formal rejection of Googleâ€™s proposal, any deal will now most likely be delayed until after the spring.
â€œThe ball is still in Googleâ€™s court,â€ Mr. Almunia said. â€œWithin a short time frame, the ball will be here, and then it will be the moment to make decisions.â€
In response, Google said its latest concessions, which are its second set after its original set was rejected in May, already addressed the concerns of the European Commission, the European Unionâ€™s executive arm.
â€œWeâ€™ve made significant changes to address the E.C.â€™s concerns, greatly increasing the visibility of rival services and addressing other specific issues,â€ Al Verney, a Google spokesman in Brussels, said in a statement.
As part of the October deal, Google would have had to give greater prominence to rivals in searches about specific topics like travel and online shopping.
Googleâ€™s competitors, including Microsoft, said on Friday that Mr. Almuniaâ€™s latest comments should push the commission to enforce existing competition rules.
â€œGoogle was offered not one but two unique opportunities to reach an agreement with the commission, and yet their actions show a deep lack of willingness to change their harmful practices,â€ said David Wood, legal counsel for Icomp, a trade body representing the Internet companies affected by Googleâ€™s practices,.
While a settlement between Google and European antitrust authorities is expected sometime next year, the negotiations are the latest effort by the European Union to crack down on alleged anticompetitive practices by American tech companies.
Brussels previously targeted Microsoft for its dominant position in both computer operating systems and web browsers, which led to sizable fines for the company. Google is trying to avoid similar penalties, which could rise to as much as $5 billion if a settlement with European lawmakers is not reached. Any wrongdoing could also limit the companyâ€™s future activities across the Continent.
Some of Googleâ€™s critics in Europe, including the Icomp trade body that has complained about its practices, claim the Internet search giant is playing for time in the hopes that rivals will not be able to compete because of Googleâ€™s dominant market position.
In response, Google says it has fulfilled the European Commissionâ€™s urgings to increase competition in the Continentâ€™s online search market. The company also avoided serious antitrust action in the United States early this year.
Google has faced a series of European regulatory headaches in recent months.
Most recently, Spanish privacy regulators fined the company $1.2 million on Thursday after local authorities found the company guilty of three violations of data privacy rules. The cases involved the inappropriate collection of personal information from a number of Google services and products in Spain.
Google also is facing similar complaints from other European privacy authorities, which claim that Google has collected individualsâ€™ data without their express consent.