[2] From 2019, Breton served as the European Commissioner for Internal Market under the presidency of Ursula von der Leyen, an appointment that met with controversy, as he was considered by anti-corruption association Anticor to be at serious risk of conflicts of interest over his previous posts at France Télécom and Atos.

[8] Breton received a master's degree in Electrical Engineering and Computer Science from École Supérieure d'Électricité (Supélec, now CentraleSupélec) in 1979 and later graduated from the Institut des hautes études de défense nationale (IHEDN).

In 1986 Breton became adviser to the French Minister of Education and Research René Monory and designed open-air science and technology theme park Futuroscope.

[11] Breton made stock offerings to generate cash and diversified the company's businesses,[12] figuring that consumer-electronics products were not high-end enough to consistently earn profits over the long term.

By the time Breton left in 2002, revenues had increased by more than 80 percent and Thomson was outperforming Sony, Matsushita, and Philips, its major consumer-electronics competitors.

[9] Widely acclaimed as a "turnaround whiz",[15][16] Breton was named by French government as head of multinational telecommunications corporation France Télécom on 2 October 2002.

As a response to these challenges Breton notably ended Orange's venture on the stock market and took back complete control over the subsidiary and its earnings.

[9] In January 2010 the Harvard Business Review first published a list of "The 100 Best-Performing CEOs in the World" which was based on an academic study comparing the performances of the heads of industry of the 2,000 biggest global companies, in their relevant fields, from 1995 to 2009.

In 2008 Atos generated a sales revenue of 5.5 billion euros with a headcount of 50,000 employees but according to Breton was "managed too compartmentally" and the company's inferior profitability margins compared to those of its competitors required a complete transformation plan.

In July 2011 Breton orchestrated the acquisition of the IT activities of German industry group Siemens, which allowed the company to rank number one among the European IT services players and in the Top 5 worldwide, with 75 000 employees in 42 countries.

[21] This acquisition, again commended by the markets (Atos’ share price rose by 6.2% and Bull's by 21.9% the day of the announcement) notably allowed the company to position itself in the supercomputing segment and to become the sole European manufacturer.

Breton received world attention after an interview with the Wall Street Journal in 2011 when he reiterated his intention to ban internal email, dubbed as "the pollution of the information age", at Atos within 18 months (known as the zero-email strategy), replacing internal emails by a set of enterprise social networks, enterprise instant messaging, collaborative tools et cetera, both being developed in-house and partially aggregated from other vendors.

Having already been proposed twice to succeed Nicolas Sarkozy as Finance Minister, Breton was appointed on 24 February 2005 while at France Telecom, replacing Hervé Gaymard.

[25] During his two and a half years at the head of Bercy, Breton centred his economic policy on the need to reform public finances, specifically to reduce debt.

A month later he set up a commission presided over by BNP Paribas CEO Michel Pébereau which was given the task of breaking the pattern of public debt.

In October 2005 Breton proposed a law on "the modernization of the economy" which was voted in the same year and looked to prioritize SMEs’ access to financial markets, encourage research and promote giving employees a stake in the company's outcomes.

On this occasion he also announced himself in favor of the status of the Societas Europaea being written into French legislation to allow businesses to operate throughout the EU on the basis of a unified set of financial rules.

At the same time he led a reform for fiscal simplification which attempted to reduce the number of tax brackets from seven to four and put in place a pre-filled internet-based declaration of revenues.

The handover of power to Jean-Louis Borloo, named as Minister of the Economy by the newly elected French President, Nicolas Sarkozy, took place the following day.

In 2008, Breton was considered for chairing Protectinvest, a private foundation in Belgium set up by billionaire Bernard Arnault to safeguard the integrity of the LVMH group until 2023.

[49] Breton and Ursula von der Leyen were described as "vaccine pirates" on social media, despite production and export figures in established news sources showing otherwise.

[50] In an attempt to resolve the issue, Breton initiated negotiations between all involved parties, i.e. the CEO of AstraZeneca Pascal Soriot, and the Dutch, Leiden-based AZ subcontractor vaccine plant, HALIX [nl].

[55][56] In July 2019, two men wearing ski masks and gloves and wielding handguns broke into Breton's Paris home, beat him and locked him up along with his wife and their live-in chauffeur.