BRUSSELS — The nominee to become the next antitrust chief for the European Union has said that keeping a close eye on American technology titans like Google and Apple will be among her top priorities if she is confirmed.
Margrethe Vestager, a former Danish economy minister, told lawmakers at the European Parliament on Thursday evening that Google was “a business with a huge, huge, huge market share,” and she signaled that she would look more deeply into whether amassing data was a factor entrenching the strength of digital companies like Google.
Personal data “is the new currency of the Internet,” Ms. Vestager told the Parliament’s influential Economic and Monetary Affairs Committee. “We should engage in not only fact-finding but much deeper understanding of these markets.”
Ms. Vestager declined to say whether she would proceed with formal charges, known as a statement of objections, against Google in a five-year-old case focused on its search and advertising businesses. But she was “absolutely certain that there will be next steps” in the Google case. As to “what kind they will be, it is too early for me to say,” she said.
Ms. Vestager’s comments on Google were sufficient to earn an endorsement on Friday morning from Burkhard Balz, a German lawmaker and a spokesman for the center-right political group on the Parliament committee. Mr. Balz said his group “would like to see strong action in investigating further into the Google case” and its members “appreciate her assurance to follow up this matter with the utmost importance.”
Ms. Vestager’s hearing is part of a lengthy process of selecting the leadership of the European Commission, the European Union’s executive arm.
Although the Parliament does not have the power to veto individual candidates, it can approve or reject the entire slate of nominees. That vote has been scheduled for Oct. 22, just a few days before new members of the commission are scheduled to take office.
A rejection by the Parliament or a delay to the vote because of wrangling among political blocs would leave the current competition commissioner, Joaquín Almunia of Spain, in place for an indeterminate period of time. The job is one of the most powerful in Brussels because the holder can directly intervene to block mergers and can order companies that form cartels or break antitrust laws to pay fines of up to 10 percent of their global annual sales.
Ms. Vestager received a mostly warm reception from lawmakers, suggesting her nomination was secure.
How much her approach would differ from Mr. Almunia’s remains to be seen. But Ms. Vestager would almost certainly be under pressure to show less patience with Google than her predecessor, as many Europeans have become more concerned with data privacy.
The digital sector was among those where “particular alertness is needed to ensure that dominant players respect the rules,” she said. “This is all the more important to allow innovation from small and medium-sized companies to flourish,” she said.
As competition commissioner, Ms. Vestager would also be responsible for preventing European Union member states from doling out market-distorting subsidies, also known as state aid, to favored companies.
This week, the commission published a report into one of the biggest state-aid cases it has undertaken: an investigation into the way Ireland may have offered Apple overly generous tax breaks dating to the early 1990s. That case, and similar investigations into the tax affairs of Starbucks in the Netherlands and of a unit of the Italian automaker Fiat in Luxembourg, “are certainly going to be priorities,” Ms. Vestager said.
Tax avoidance by multinationals is “a very, very serious issue,” she added.
In the antitrust allegations against Google, the search giant could theoretically face a fine of nearly $6 billion. Fines have never gone that high, but antitrust experts say that such penalties are set to rise. In June, the second-highest court in the European Union upheld a 1.06 billion euro, or $1.34 billion, fine against Intel, representing 4 percent of the maximum penalty.
Last month, Mr. Almunia was forced to postpone a deal with Google that he announced in February after an outcry from powerful German and French publishers and from rival technology companies like Microsoft and Yelp.
Those companies said that the core of the deal between Google and Mr. Almunia — a system that would more prominently display rivals’ search services for finding hotels and for shopping, among others, when people conduct Google searches — would do little to help them compete more effectively in Europe, where, in many countries, Google powers more than 90 percent of searches.
Because of an editing error, an earlier version of this article referred incorrectly to the company that theoretically could face a $6 billion fine in a European antitrust case. It is Google, not Apple.