Private company

Siemens Enterprise Communications

Logo: Unknown author Unknown author, Public domain, via Wikimedia Commons3

Telecommunications company

Unify is a telecommunications company focused on enterprise unified communications. It is headquartered in Munich, Germany, and is subsidiary of Mitel since 2023. It was known as Siemens Enterprise Communications (SEN) until January 21, 2016, it was a joint venture between The Gores Group and Siemens.2 It is part of Atos SE.1 Wikipedia text CC BY-SA 4.0

Last updated Oct 20, 2026.

Overview

2008Founded1

Unify is a telecommunications company focused on enterprise unified communications. It is headquartered in Munich, Germany, and is subsidiary of Mitel since 2023. It was known as Siemens Enterprise Communications (SEN) until January 21, 2016, it was a joint venture between The Gores Group and Siemens. Originally announced July 29, 2008, SEN started operating in 2013, with Gores having a 51% stake, while Siemens had 49%. In October 2023, Mitel completed the purchase of the company.2

Corporate structure

Siemens Enterprise Communications is part of a group headed by Atos SE. 66 entities, 19 countries on record. Switch between the flow chart and the network, and select any entity to see its details.

  • Atos SE Bezons, France
    • Siemens Enterprise Communications Munich
    • Atos (United States) Subsidiary · Purchase, United States
    • DataSentics Subsidiary · Praha, Czechia
    • science+computing ag Subsidiary · Tübingen, Germany
    • 'Eviden株式会社 Subsidiary · Bezons, France
    • ATOS Subsidiary · Bezons, France
    • ATOS (AUSTRALIA) PTY LTD Subsidiary · Melbourne, Australia
    • Atos Belgium Subsidiary · Zaventem, Belgium
    • ATOS BILISIM VE DANISMANLIK ANONIM SIRKETI (ATOS BİLİŞİM VE DANIŞMANLIK ANONİM ŞİRKETİ) Subsidiary · Bezons, France
    • ATOS BRASIL LTDA. Subsidiary · Bezons, France
    • ATOS CONSULTING LIMITED Subsidiary · London, United Kingdom
    • ATOS FRANCE Subsidiary · Bezons, France
    • Atos Germany Subsidiary · Germany
    • ATOS GLOBAL IT SOLUTIONS AND SERVICES PRIVATE LIMITED Subsidiary · Mumbai, India
    • ATOS HOLDING UK 1 LIMITED Subsidiary · St. Helier, Jersey
    • ATOS INFORMATION TECHNOLOGY (CHINA) CO., LTD Subsidiary · Bezons, France
    • ATOS INFORMATION TECHNOLOGY (SINGAPORE) PTE. LTD. Subsidiary · Singapore, Singapore
    • Atos Information Technology GmbH Subsidiary · Bezons, France
    • ATOS INFORMATION TECHNOLOGY HK LIMITED Subsidiary · Bezons, France
    • ATOS INFORMATION TECHNOLOGY INC. Subsidiary · Bezons, France
    • ATOS INTERNATIONAL Subsidiary · Bezons, France
    • ATOS INTERNATIONAL B.V. Subsidiary · Amstelveen, Netherlands
      • Atos Croatia drustvo s ogranicenom odgovornoscu za informaticku tehnologiju Subsidiary · Zagreb, Croatia
    • ATOS INVESTISSEMENT 19 Subsidiary · Bezons, France
    • ATOS IT OUTSOURCING SERVICES, LLC Subsidiary · Bezons, France
    • ATOS IT SERVICES SPÓŁKA Z OGRANICZONĄ ODPOWIEDZIALNOŚCIĄ Subsidiary · Bezons, France
    • and 38 more

Built from parent and subsidiary links from GLEIF, the Global Legal Entity Identifier Foundation (CC0); subsidiaries, stakes and holdings from Wikidata (CC0). Each entity in the chart links to its source.

The story

Background: heritage (1847–2006)

Siemens Communications traces its origins to Siemens & Halske (German legal name: Telegraphen-Bauanstalt von Siemens & Halske), founded by Werner von Siemens on 12 October 1847. Siemens' first invention was the pointer telegraph. In the latter half of the 19th century, the company built long-distance telegraph lines, encompassing major projects in Germany and Russia, and the monumental Indo-European telegraph line stretching over 11,000 km from London to Calcutta. In 1897, Siemens & Halske went public.

During the first half of the 20th century, the company undertook a series of mergers and spin-offs, leading to the formation of three separate companies. The original company, Siemens & Halske, focused on communications engineering. Siemens-Schuckertwerke was founded in 1903 to develop electric power engineering. Finally, in 1932, Siemens-Reiniger-Werke was founded to specialize in electro-medical equipment. In 1966, through a major restructuring process, these main companies merged to form Siemens.

In the late 1970s, Siemens focused on information and communications technology (ICT). In 1978, it established Siemens Communication Systems, which, in 1985, was reorganized into two divisions: Siemens Communication Systems for public network products, and Siemens Information Systems for PBX and computer-related products. Entering the globalization era of the 1990s, these two divisions made acquisitions. In 1989, the PBX division initiated a structured purchase of ROLM from IBM, renaming it ROLM Systems, and completed the purchase in 1992 as Siemens-ROLM Communications. The same year, the company acquired a 40% stake in GEC Plessey Telecommunications (GPT) which evolved into the UK operations of the current company. In 1991, the carrier networks division acquired Stromberg-Carlson from The Plessey Company plc. In 1996, the PBX businesses of Mercury Communications, a subsidiary of UK-based Cable & Wireless, were also acquired.

In late 1998, Siemens undertook a major restructuring into four main divisions: power generation, industry, rail systems, and information and communications (ICN). As part of the ICN Division, Siemens Information & Communication Networks (SICN) – later to be commonly known as Siemens Communications (Siemens COM) – became Siemens's biggest business unit. Its focus was on Internet-based network technologies, as it was predicted that global data traffic volume would surpass voice telephony traffic in the early part of the 21st century. In addition, Siemens COM placed greater emphasis on the US market, dominated at the time by Nortel, Lucent, and the emerging Cisco; to that end, the company made two American acquisitions, Castle Networks and Argon Networks, in 1999.

In March 2002, Siemens Communications was divided into two major business units: one for public mobile networks and fixed networks, and the other for enterprise networks.

Siemens Enterprise Communications (2006–2013)

The evolution of Siemens Enterprise Communications began in June 2006, when Siemens divided Siemens COM into two pieces. The carrier networks business was merged with Nokia's Network Business Group to form a joint venture, Nokia Siemens Networks. In October 2006, Siemens Enterprise Communications was created as a wholly owned subsidiary of Siemens. From that time, the business focused on unified communications.

In July 2008, Siemens announced a joint venture with American private equity company The Gores Group (headed by Alec Gores), integrating two Gores Group businesses, Enterasys Networks and SER Solutions. Enterasys operated as a subsidiary of Siemens Enterprise Communications until September 2013, when Extreme Networks announced an agreement to purchase Enterasys in an all-cash transaction valued at US$180 million.

Unify (2013–present)

In October 2013, Siemens Enterprise Communications was rebranded to Unify.

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In November 2015 it was announced that IT services company Atos would purchase Unify from The Gores Group/Siemens for 340 million euro. The acquisition was completed in January 2016.

In January 2023, Atos announced it entered into exclusive negotiations with Mitel for the sale of its Unified Communications & Collaboration business (Unify).

Mitel filed for Chapter 11 bankruptcy protection on March 10, 2025, listing assets and liabilities between $1 billion and $10 billion. On June 20, 2025, Mitel exited bankruptcy following the completion of its restructuring plan.

From Wikipedia’s article on Unify (company), shared under CC BY-SA 4.0.4

Products and brands

  • networking hardware

Listed on Wikidata.1

Unify is a communications provider that develops, deploys, and manages unified communications, network infrastructure and security and managed and professional services for large enterprises and small and medium enterprises, both directly and via partners.

Its primary product brands are OpenScape (unified communications applications), HiPath (converged enterprise communications) and Circuit (SaaS Team Communication). The company announced OpenScape with Microsoft in 2003. Unify demonstrated SIP and service-oriented architecture with OpenScape. The company's services cover managed services, professional services, and maintenance and support services.

In 2014, Unify launched a SaaS team communication product called Circuit which was previously codenamed Project Ansible. By agreement between the new owner Atos and former owner, from 2016 Circuit was further developed on-the-go and in 2017 launched as a unified communication and collaboration platform for the whole of Siemens.

From Wikipedia’s article on Unify (company), shared under CC BY-SA 4.0.4

Subsidiaries and ownership

Parent company

Owners

Former owners and parents

From Wikidata.1

Timeline

  1. 2008Founded Founded1