3U Holding AG, together with its subsidiaries, provides telecommunication and information technology services in Germany and internationally. It operates in three segments: Information and Telecommunications Technology (ITC); Renewable Energies; and Heating, Ventilation, and Air Conditioning (HVAC). The ITC segment provides voice retail, voice business, and data center and managed services, as well as trades in IT licensing. The Renewable Energies segment engages in the development of wind power projects and generation of electricity from its wind and solar energy plants. The HVAC segment sells and distributes heating, ventilation, and air conditioning systems to wholesalers, tradespeople, and DIYers through its online stores. 3U Holding AG was founded in 1997 and is headquartered in Marburg, Germany.