BRUSSELS -- Google is facing a new antitrust complaint in Europe, this time over its software for mobile devices, as regulators on this side of the Atlantic continue their scrutiny of the U.S. tech giant.
The disclosure comes as Google takes the final steps aimed at resolving European Union charges that it abused its dominance of the Internet search field, the European Union's competition commissioner, Joaquín Almunia, said in an interview Monday.
It also comes as the U.S. Treasury secretary, Jacob J. Lew, met with the Union's officials in Brussels in part to discuss a free-trade agreement. Antitrust issues are not expected to be part of those talks, but European regulators have historically taken a harder line on technology companies than their American counterparts.
In the interview, Mr. Almunia said officials had been examining Google's Android operating system independently of its two-year inquiry into the Internet search field, but he refused to comment on the new complaint.
Mr. Almunia did say that he was receiving proposals by Google this week to clear up concerns about its search practices that he hoped would make it easier for Internet users to identify when Google was promoting its own services rather than those of competitors who might offer better results.
Those proposals also were expected to involve marking services promoted by Google and to give any providers of online content greater leverage when Google wants to use their material.
In settling similar charges with U.S. regulators last year, Google was not required to make such concessions.
A Google spokesman, Al Verney, would not discuss the new complaint or the comments by Mr. Almunia about the search case specifically, saying only that the company continued "to work cooperatively" with the commission.
The new complaint was filed by Fairsearch Europe, a group of Google's competitors, including the mobile phone maker Nokia, the software titan Microsoft and others, like Oracle. The complaint accuses Google of using Android "as a deceptive way to build advantages for key Google apps in 70 percent of the smartphones shipped today," said Thomas Vinje, the lead lawyer for Fairsearch Europe, referring to Android's market share in the smartphone market.
"Google's goal is to dominate consumers' Internet experience and consumer data as usage shifts from desktop to mobile," said Mr. Vinje. "We are asking the commission to move quickly and decisively to protect competition and innovation in this critical market."
The concerns about Android are focused on the way Google might be requiring exclusive terms for the placement of certain applications, or programs that mobile users can download onto their phones.
For example, phone makers that agree to take Android -- and that also want other must-have Google applications like YouTube -- face contractual requirements to place those applications and other Google-branded applications in a prominent position on the mobile device desktop, according to Mr. Vinje.
He said the new complaint represented a potentially far greater challenge to Google at a time when mobile devices were becoming the primary way that users gain access to information.
In the interview, Mr. Almunia focused his comments on the commission's inquiry into the Internet search sector.
In order to reach a settlement, Google needed to offer the commission a solution where choices between Google-branded search results, and those of its competitors, were clearly visible within the search engine both on desktop computers and on mobile devices, he said.
"I don't know if you should call it labeling, or whatever, but they need to distinguish," Mr. Almunia said, describing how Google needed to differentiate between its own services and those of its competitors.
"In some cases this can be achieved through the information you will receive through the natural search results," he said. "In other cases, maybe we will ask Google to signal what are the relevant options, alternative options, in the way they present the results."
The choice "should be a real one," he said, referring to the search results.
He declined to elaborate further but said that discussions about how the remedies should operate could still take place if improvements in Google's proposals were needed. He said the system would not require Google to make changes to its algorithm, which is the complicated formula that the company uses to determine results that best answer the search query.
Mr. Almunia also said he wanted Google to allow any producer to opt out of having their material used by Google in its search results without facing a backlash from the search giant.
Web sites and some publications have complained in recent years of virtually disappearing from Google's search engine if they posed a competitive threat or did not comply with its Google's terms.
Mr. Almunia said he would test those proposals by sending questionnaires to competitors, including to the complainants, and to other companies. "This is a new step in the investigation," Mr. Almunia said.
The commission has taken a tougher line with Google than has the U.S. Federal Trade Commission on the issue of how Google runs its search rankings. The F.T.C. decided in January that Google had not broken antitrust laws after a 19-month inquiry into how the company operated its search engine.
Mr. Almunia said in Europe, where Google is especially strong, with more than 90 percent of the search market, compared with about 70 percent in the United States, it is particularly difficult for search engines to establish themselves if they focus on narrow but deep services like online shopping, travel, mapping or other vertical categories. But Mr. Almunia also insisted that his approach was not aimed at "protecting competitors," as critics of European regulation have long complained.
In terms of "scraping" content, the normal way Google uses and displays snippets of information from other Web sites in its search results, Mr. Almunia said he expected Google to accept that other companies can choose "to allow or not to allow Google to use the content, but this decision cannot have as a consequence the punishment of those who will not allow the use of the content in terms of search results."
Mr. Almunia said he had concerns that Google had abused its dominance to promote its own products, but he would not need to "find a final answer to this question" if Google reached a settlement. "We are concerned by the possibility of an abuse," he said.
"What is clear in our view is the market dominance of Google," Mr. Almunia said. "This is obvious."
He also noted that "it would not be surprising" if Google faced formal charges in a case concerning Motorola Mobility, a mobile phone maker owned by Google. That case follows complaints by Microsoft and Apple that they were victims of unfair licensing conditions and abusive litigation by Motorola Mobility.
This article originally appeared in The New York Times.