Michael Claus Wisser

AVECO Holding AG engages in the provision of airport, facility management, and industrial services. The airport services include ground handling, aircraft cleaning, and cargo handling. The facility management services encompass building technology, cleaning, security, catering, and garden maintenance. The industrial services involve building, ventilation, and electrical engineering; maintenance and repair of machines; production support; and logistics. The company was founded by Claus Wisser in 1991 and is headquartered in Frankfurt, Germany.

WISAG Service Holding GmbH & Co. KG provides facility management, airport, and building operating technology, cleaning and security services. The company was founded by Claus Wisser in 1965 and is headquartered in Frankfurt am Main, Germany.

WISAG Dienstleistungsholding SE engages in the provision of airport, facility, and industrial services. The firm operates through the following segments: Aviation, Facility, and Industry. The Aviation segment includes airport, ground, passage, cargo, and personnel services. The Facility segment focuses on technical and infrastructural services for commercial, infrastructure, and residential properties. The Industry segment specializes in maintenance, technical cleaning, infrastructural and industrial facility management, electrical engineering, building technology, production logistics, as well as production support and industrial assembly. The company was founded by Claus Wisser on March 15, 1965 and is headquartered in Frankfurt, Germany.

Arthur Andersen LLP used to provide accounting services. It was also into consulting services for clients that operate businesses throughout the United States and around the world. Arthur Andersen was founded in 1913 and was headquartered in Chicago, IL.

Part of AVECO Holding AG, ASG Airport Service GmbH is a ground handling German company that provides aircraft cleaning and flight services. The private company is based in Frankfurt am Main, Germany. The company was founded in 1995. The CEO is Michael Dietrich.

Wisag Gebäudereinigung GmbH provides cleaning services. Its services include facility management, building cleaning, catering, and consulting and management services. The company is headquartered in Linz, Austria.