By James Kanter
BRUSSELS — Jean-Claude Juncker, the incoming president of the European Union’s executive branch, nominated his team on Wednesday, which will face challenges including reviving the flagging euro-area economy, curbing reliance on Russian energy and controlling migration into the bloc.
The nominations come as part of the changes in European Union governance that occur every five years, and follow the election in May of a new European Parliament. Mr. Juncker’s nominees are subject to approval by the Parliament, which is expected to hold hearings on each appointee — but can only accept or reject the entire slate, rather than approve some nominations while blocking others.
Among the most coveted posts doled out by Mr. Juncker were those that oversee the European economy.
One of the most powerful positions is that of enforcer of the bloc’s far-reaching antitrust laws, a job that would go to Margrethe Vestager, a former economy minister of Denmark. She would take over from Joaquín Almunia of Spain in deciding whether giant American technology companies like Google and energy titans like Gazprom of Russia should be fined for abusing dominant market positions in Europe.
A closely watched nomination was for the oversight of economic and financial affairs, with authority to review budget plans for countries in the euro currency union. That post went to Pierre Moscovici, a Socialist and former French minister of finance, who would succeed Olli Rehn of Finland.
Mr. Juncker, a former prime minister of Luxembourg, is scheduled to take over as the president of the European Commission in November. He succeeds José Manuel Barroso, who has been widely criticized in countries like Britain for failing to curb bureaucratic overreach.
“We have to be open to change,” Mr. Juncker said in a news release on Wednesday. “We have to show that the commission can change.”
In other important economics jobs, the nominee for the trade portfolio is Cecilia Malmstrom of Sweden, who would replace Karel De Gucht of Belgium in leading talks on a far-reaching trade agreement with the United States. The discussions face widespread opposition among Europeans, who say any deal would threaten environmental and health standards.
In an apparent victory for the British, the oversight of other aspects of financial services and capital markets would be given to Jonathan Hill, a member of Britain’s Conservative Party. He would take over from Michel Barnier of France in a sensitive role that includes deciding how banks in financial centers like the City of London should be regulated. Putting a Briton in that job might help win support in the City for keeping Britain in the European Union.
The nominee for overseeing digital policy is Günther H. Oettinger of Germany, who would oversee the telecommunications sector and sensitive copyright issues of concern to online publishers. European Union officials said that a push by the European Union to rein in the way American technology giants like Facebook and Google use and share citizens’ personal data probably would fall within the responsibilities of Vera Jourova, the nominee for the post of commissioner for justice.
A Greek nominee, Dimitris Avramopoulos, who has served as his country’s defense minister, was selected to oversee migration and home affairs.
European commissioners wield huge influence by proposing and enforcing laws on matters as wide-ranging as online privacy, how much carbon dioxide cars can emit and even the way cellphone calls are priced. They can also take countries to court for breaking European Union laws.
But the composition of the commission has been made vastly more complex by the addition this time of vice presidents who would have enhanced powers and would be tasked with overseeing colleagues’ agendas and with vetting their legislative proposals. That could turn out to be unwieldy and divisive.
Nominees for the vice-presidential positions include: the former prime minister of Estonia, Andrus Ansip, for digital issues; the former prime minister of Latvia, Valdis Dombrovskis, for policies concerning the single currency; the former prime minister of Slovenia, Alenka Bratusek, for energy; the Dutch foreign minister, Frans Timmermans, as a “first vice-president” in charge of streamlining regulation; and the current commissioner for international cooperation, Kristalina Georgieva of Bulgaria, to oversee budgetary issues.
At a news conference on Wednesday, Mr. Juncker highlighted the central role assigned to Mr. Timmermans, whose speech at the United Nations in July is credited with uniting fractious European Union countries in a way that led to the imposition of sanctions on Russia after the shooting down of a Malaysian jetliner over Ukraine.
Mr. Timmermans “will be my right-hand man,” Mr. Juncker said.
Jyrki Katainen, a former Finnish prime minister who is currently in charge of the economic portfolio, will also help oversee the main economic portfolios in the new commission and will marshal investment to jump-start growth.
Mr. Juncker stressed the importance of teamwork for his new roster of appointees. “In the new commission,” he said, “there are no first or second-class commissioners — there are team leaders and team players.”
The jostling among member states for the top jobs — each country can nominate only one commissioner — was ferocious. Those national demands had to be balanced against those of the European Parliament, which also called for a sufficient number of women in the top posts.
The rise of Mr. Moscovici is seen as a victory for France, whose government has pushed for more flexibility in the rule book for the euro, even as it struggles to meet those rules, much to Germany’s consternation. As it happened, on Wednesday, the French government said it would not be able to bring its budget deficit down to the European Union limit of 3 percent of gross domestic product until 2017, two years later than it had originally forecast.
The process of selecting the commissioners for highly specific portfolios is a painstaking task and can seem somewhat arbitrary, with each member state pushing for its candidate to take a top jobs.
Late last month the Italian foreign minister, Federica Mogherini, who had been in that position for just a few months, was named as the European Union’s foreign policy chief despite concerns that she was too inexperienced. Her selection came after a strong push by Matteo Renzi, the prime minister of Italy, which currently holds the rotating presidency of the European Union.
Ms. Mogherini will be a member of the European Commission, but her nomination was made by European Union heads of state, who have a direct say in the selection for the foreign policy post.
Mr. Juncker, for that matter, was selected by European Union leaders in June over the objections of Prime Minister David Cameron of Britain.
Mr. Juncker has said that he plans major initiatives in his five-year term, including better integrating the bloc’s capital markets to lower borrowing costs and to free up lending, and mobilizing 300 billion euros, or $387 billion, of public and private investment in the next three years to bolster growth.