In the 1950s and from their new base in Bavaria, S&H started to manufacture computers, semiconductor devices, washing machines, and pacemakers.
In 1966, Siemens & Halske (S&H, founded in 1847), Siemens-Schuckertwerke (SSW, founded in 1903) and Siemens-Reiniger-Werke (SRW, founded in 1932) merged to form Siemens AG.
The company's first digital telephone exchange was produced in 1980. In 1988 Siemens and GEC acquired the UK defence and technology company Plessey. Plessey's holdings were split, and Siemens took over the avionics, radar and traffic control businesses — as Siemens Plessey.
In 1985 Siemens bought Allis-Chalmers' interest in the partnership company Siemens-Allis (formed 1978) which supplied electrical control equipment. It was incorporated into Siemens' Energy and Automation division.
In 1991, Siemens acquired Nixdorf Computer AG and renamed it Siemens Nixdorf Informationssysteme AG.
In October 1991, Siemens acquired the Industrial Systems Division of Texas Instruments, Inc, based in Johnson City, Tennessee. This division was organized as Siemens Industrial Automation, Inc., and was later absorbed by Siemens Energy and Automation, Inc.
In 1997 Siemens introduced the first GSM cellular phone with colour display. Also in 1997 Siemens agreed to sell the defense arm of Siemens Plessey to British Aerospace (BAe) and a UK government agency, the Defence Analytical Services Agency (DASA). BAe and DASA acquired the British and German divisions of the operation respectively.
In 1999, Siemens' semiconductor operations were spun off into a new company known as Infineon Technologies. Also, Siemens Nixdorf Informationssysteme AG formed part of Fujitsu Siemens Computers AG in that year. The retail banking technology group became Wincor Nixdorf.
In 2000 Shared Medical Systems Corporation was acquired by the Siemens' Medical Engineering Group, eventually becoming part of Siemens Medical Solutions.
Also in 2000 Atecs-Mannesman was acquired by Siemens, The sale was finalised in April 2001 with 50% of the shares acquired, acquisition, Mannesmann VDO AG merged into Siemens Automotive forming Siemens VDO Automotive AG, Atecs Mannesmann Dematic Systems merged into Siemens Production and Logistics forming Siemens Dematic AG, Mannesmann Demag Delaval merged into the Power Generation division of Siemens AG. Other parts of the company were acquired by Robert Bosch GmbH at the same time.
In 2001 Chemtech Group of Brazil was incorporated into the Siemens Group, the company provides industrial process optimisation, consultancy and other engineering services
In 2003 Siemens acquired the flow division of Danfoss and incorporated it into the Automation and Drives division. Also in 2003 Siemens acquired IndX software (realtime data organisation and presentation).The same year in an unrelated development Siemens reopened its office in Kabul. Also in 2003 agreed to buy Alstom Industrial Turbines; a manufacturer of small, medium and industrial gas turbines for 1.1 billion Euro.
In 2004 the wind energy company Bonus Energy in Brande, Denmark was acquired,forming Siemens Wind Power division.Also in 2004 Siemens invested in Dasan Networks (South Korea, broadband network equipment) acquiring ~40% of the shares,Nokia Siemens disinvested itself of the shares in 2008. The same year Siemens acquired Photo-Scan (UK, CCTV systems) US Filter Corporation (water and Waste Water Treatment Technologies/ Solutions, acquired from Veolia), Hunstville Electronics Corporation (automobile electronics, acquired from Chrysler), and Chantry Networks (WLAN equipment)
In 2005 Siemens sold the Siemens mobile manufacturing business to BenQ, forming the BenQ-Siemens division. Also in 2005 Siemens acquired Flender Holding GmbH (Bocholt, Germany, gears/industrial drives), Bewator AB (building security systems), Wheelabrator Air Pollution Control, Inc. (Industrial and power station dust control systems),AN Windenegrie GmbH. (Wind energy),Power Technologies Inc. (Schenectady, USA, energy industry software and training), CTI Molecular Imaging (Positron emission tomography and molecular imaging systems), Myrio (IPTV systems), Shaw Power Technologoes International Ltd (UK/USA, electrical engineering consulting, acquired from Shaw Group), and Transmitton (Ashby de la Zouch UK, rail and other industry control and asset management).
In 2006, Siemens announced the purchase of Bayer Diagnostics, which was incorporated into the Medical Solutions Diagnostics division on 1 January 2007,also in 2006 Siemens acquired Controlotron (New York) (ultrasonic flow meters) Also in 2006 Siemens acquired Diagnostic Products Corp., Kadon Electro Mechanical Services Ltd. (now TurboCare Canada Ltd.), Kühnle, Kopp, & Kausch AG, Opto Control, and VistaScape Security Systems.
In March 2007 a Siemens board member was temporarily arrested and accused of illegally financing a business-friendly labour association which competes against the union IG Metall. He has been released on bail. Offices of the labour union and of Siemens have been searched. Siemens denies any wrongdoing.In April the Fixed Networks, Mobile Networks and Carrier Services divisions of Siemens merged with Nokia's Network Business Group in a 50/50 joint venture, creating a fixed and mobile network company called Nokia Siemens Networks. Nokia delayed the merger due to bribery investigations against Siemens. In October 2007, a court in Munich found that the company had bribed public officials in Libya, Russia, and Nigeria in return for the awarding of contracts; four former Nigerian Ministers of Communications were among those named as recipients of the payments. The company admitted to having paid the bribes and agreed to pay a fine of 201 million euros. In December 2007, the Nigerian government canceled a contract with Siemens due to the bribery findings.
Also in 2007 Siemens acquired Vai Ingdesi Automation (Argentina, Industrial Automation), UGS Corp., Dade Behring, Sidelco (Quebec, Canada), S/D Engineers Inc., and Gesellschaft für Systemforschung und Dienstleistungen im Gesundheitswesen mbH (GSD) (Germany).
In July 2008, Siemens AG announced a joint venture of the Enterprise Communications business with the Gores Group. The Gores Group holding a majority interest of 51% stake, with Siemens AG holding a minority interest of 49%.Also acquired in 2008 was SG Wasseraufbereitung und Regenerierstation GmbH (SG Water).
In April 2009, Fujitsu Siemens Computers became Fujitsu Technology Solutions as a result of Fujitsu buying out Siemens' share of the company.