Europe Warns Google It Could Face Further Concessions BRUSSELS - The European Union's top antitrust official warned Google on Tuesday that the American company might need to make further concessions to settle a case concerning its hugely lucrative online search and advertising businesses. Without those additional concessions, Joaquín Almunia, the European Union competition commissioner, told a committee meeting at the European Parliament that Google could face formal charges for violating European competition law. Mr. Almunia's comments, in response to a question during scheduled testimony at Parliament, highlight the pressure from rivals like Microsoft to devise a tougher set of remedies than those worked out with Google. Those proposed solutions were made public last month by the European Commission. If critics of Google in Europe remain dissatisfied with the settlement, they could go to court. They could sue the European Commission, accusing it of failing to push hard enough for an effective solution. Final judgments in such cases can take years. On Tuesday, Mr. Almunia told Parliament that he was still reviewing feedback from companies and organizations involved in the case. Market testing was undertaken to see if, among other issues, the proposed remedies addressed complaints that Google favored its own products in search results. But Mr. Almunia signaled his intention to make firmer demands in some areas of the proposed settlement. "After we have analyzed the responses we have received," Mr. Almunia said, "we will ask Google, probably, I cannot anticipate this formally, but almost 100 percent, we will ask Google: you should improve your proposals." Mr. Almunia said that the period of market testing, which was to have ended on Monday, had been extended by one month at the request of some of the participants in the case. A major element of the settlement involves Google's showing links to the Web sites of competitors who offer specialized search services. In cases where Google sells advertising adjacent to search results for specific industries like restaurants and hotels, Google would provide a menu of at least three options for non-Google search services. In addition, Google would label results that pointed to its own services - like Google Maps, if they displayed local businesses - as Google properties and separate them from general search results with a box, though they would still appear in the normal list of results. Google's agreement would be legally binding for five years, and a third party, approved by the commission, would be put in place to monitor compliance. Al Verney, a spokesman for Google, said Tuesday that the company's proposal already "clearly addresses the four areas of concern that were raised" by Mr. Almunia. Google was continuing to "work with the commission to settle this case," Mr. Verney said. Mr. Almunia also said that he expected to hold a series of "exchanges" with the search giant. Google would then need to "send us the proposals that we consider can solve the concerns," he added. Those proposals could lead to a legally binding settlement by the end of the year. Previously, European Union officials said that a binding settlement could be reached by the summer. Even if Google reached a binding settlement with Mr. Almunia, Google could still face a fine of as much as 10 percent of its global annual sales, which were nearly $50 billion last year, if it broke its promises. But a deal would allow Google to escape the long, expensive antitrust battles that Microsoft fought in Europe over its media player and server software during the last decade.