Siemens completes $10bn Altair software acquisition

A completed purchase for the software portfolio

Siemens has completed its purchase of Altair Engineering, the industrial software business headquartered in Troy, Michigan, in the United States. The transaction supports the German technology group’s expansion in industrial software and artificial intelligence. President and chief executive Roland Busch described Altair as Siemens’ largest acquisition to date. Altair’s technology will join the Siemens Xcelerator digital business platform, which brings together software and connected industrial capabilities.

The purchase forms part of Siemens’ One Tech Company programme, launched in 2024 to increase digital revenue through investment in AI-enabled products and connected hardware. Busch linked the combination to the development of Siemens’ digital twin offering, extending its software activities. Altair was founded in 1985 as a consulting business serving Detroit’s automakers and went public in 2017. Its subsequent activities included simulation, data science and high-performance computing.

Siemens company logo

Simulation and computing capabilities

Siemens confirmed completion on 26 March 2025 at an enterprise value of approximately US$10 billion. The company identified several areas being added to its industrial software portfolio:

Mechanical and electromagnetic simulation;
High-performance computing;
Data science and artificial intelligence.

The acquired software is intended for users ranging from engineers to generalists. Siemens expects the combination to make simulation expertise more accessible, help customers optimise computing processes and support the creation of analytical and AI tools. These are the company’s expectations for the combined offering, rather than measured customer results disclosed at closing. Siemens linked the transaction to research and development investment in software, connected hardware and sustainability. The group, based in Berlin and Munich in Germany, generated revenue of €75.9 billion in fiscal 2024, which ended on 30 September 2024.

The agreement and its original expectations

Siemens announced the acquisition agreement on 30 October 2024. Altair shareholders were to receive US$113 per share in cash. The offer represented a 19% premium to the unaffected closing price on 21 October 2024, the last trading day before media reports about a possible transaction. The approximately US$10 billion figure described enterprise value. Siemens initially expected the transaction to close in the second half of calendar 2025, subject to customary conditions; the actual completion announcement came in March.

At signing, chief financial officer Ralf P. Thomas expected the purchase to increase earnings per share before purchase-price accounting effects by the second year after closing. Siemens also targeted annual cost synergies exceeding US$150 million, measured as an EBITDA impact, by that second year. Those October expectations concerned future financial effects. They were distinct from the completed ownership transaction and did not establish that the targeted savings or earnings contribution had already been achieved.