The company and its name (originally spelled Alsthom) was formed by a merger between the electric engineering division of Société Alsacienne de Constructions Mécaniques (Als) and Compagnie Française Thomson-Houston (thom) in 1928.

As a result, Alstom was compelled to dispose of several of its divisions, including shipbuilding and electrical transmission to Areva,[4] in order to comply with European Union rules on state aid.

Alsthom was founded in 1928 from the merger of the French heavy engineering subsidiary of the Thomson-Houston Electric Company, the Compagnie française Thomson Houston, CFTH, and of the Société Alsacienne de Constructions Mécaniques.

It also set the world endurance record for high-speed train lines in 2001, travelling the 1,067.2 kilometres (663.1 mi) from Calais to Marseille in 3 hours and 29 minutes.

[7] During the early-1990s, GEC Alsthom was the principal manufacturer of the British Rail Class 373, a variant of their TGV family specially designed for traversing the Channel Tunnel between the UK and France.

Although collectively operated by Eurostar, the type was ordered by three different railway companies: 16 by SNCF, four by NMBS/SNCB, and 18 by British Rail, of which seven were shortened North of London sets.

Alstom also bought Canada's Télécité,[citation needed] a passenger information and security solutions company, and sold its heavy-duty gas turbine business to General Electric.

These heavy debts were largely due to a $4 billion charge over a design flaw in a turbine developed by ABB, acquired by Alstom in 2000, as well as the collapse of customer Renaissance Cruises amid a general downturn in the marine market.

[25][26] European competition commission law required Alstom to sell several of its subsidiaries, including its shipbuilding and electrical transmission assets, when it accepted a €3.2 billion rescue plan involving the French state.

[28] The company sold its electrical transmission and distribution ("grid") activities to Areva, the diesel locomotive manufacturer Meinfesa to Vossloh, and Alstom Power Rentals to APR LLC.

[48][49] In 2014, Alstom sold its steam auxiliary components activities (air preheaters and gas-gas heaters for thermal power, other industrial heat transfer equipment, and grinding mills) to Triton Partners for €730 million.

He was accused of willful blindness of his company's suspected corruption and was imprisoned in a high security facility for 14 months and denied release on bail until the week of Alstom's acquisition by the US conglomerate General Electric.

[54][55] In late 2014, Alstom was fined $772 million by the DOJ, and admitted guilt under the Foreign Corrupt Practices Act in relation to bribes paid to obtain contracts in various countries.

[60] In December 2018, three executives of Alstom were found guilty of conspiracy to corrupt following an investigation by the SFO into allegations of several Lithuanian politicians and officials being offered bribes in return for securing contracts.

[62][63] Alstom has been listed on the database in light of its involvement in activities related to "the provision of services and utilities supporting the maintenance and existence of settlements" and "the use of natural resources, in particular water and land, for business purposes".

[62][63] On 5 July 2021, Norway's largest pension fund KLP said it would divest from Alstom together with 15 other business entities implicated in the UN report for their links to Israeli settlements in the occupied West Bank.

[74] On 5 May 2014, the French government stated it did not back GE's bid, citing concerns on the future of Alstom's rail division as a smaller separate entity, suggesting that GE transfer its own rail division to Alstom; other concerns were over the civil nuclear field's national independence, and French jobs.

[note 1]), nicknamed "décret Alstom", extending to power of the state to veto the takeover of "strategic interests" into areas of energy supply, water, transport, telecoms and public health.

[80][81] Both the French employer organisation MEDEF and the European Commissioner for Internal Market and Services (Michel Barnier) responded negatively to the decree.

The proposal included an offer to buy a further 10% stake from shareholder Bouygues and an option to form a rail transport joint venture.

[82] On 19 June, GE revised its bid, matching the same price with a lower cash transaction value; it also proposed forming a joint venture of their renewable, electric grid, steam turbine and nuclear power businesses.

[98] In September 2015, it was announced that Amtrak would award Alstom a contract for $2.5 billion for the next generation high-speed train sets for the Northeast Corridor.

[101] In March 2016, a joint venture of Alstom and Gibela began construction of a new 60,000 square metres (650,000 sq ft) train building factory in Dunnotar, outside of Johannesburg, South Africa.

[109] The combined rail business, which was to have been reportedly named Siemens Alstom and headquartered in Paris, would have $18 billion U.S. in revenue and employ 62,300 people in more than 60 countries.

[111] The proposed merger was viewed by some as a measure to counter the rise of rival Chinese rail business CRRC; it reportedly received support from many figures within both the French and German governments.

[112] The transaction, which was originally due to close by the end of 2018, was met with opposition by French trade union officials who voiced their concerns that such a merger would have the potential for job losses.

[115] In response to this ruling, Alstom's Chief Executive Officer Henri Poupart-Lafarge stated that he viewed the decision to block the merger was a result of "ideological prejudices".

[119] Alstom has developed a ground-level power supply (alimentation par le sol - APS) system for use with buses and other vehicles.

In September 2015, it was announced in Hornell, New York, by Senator Charles Schumer (D-NY) that Amtrak will be awarding Alstom a contract for $2.45 billion for the next-generation high-speed train sets for the Northeast Corridor.

[133] In Brazil, Alstom, together with Bardella, ran a joint venture called Indústria Metalúrgica e Mecânica da Amazônia to build hydroelectric power plants throughout the Amazon and Latin American regions.