Managing Director: Ralph Hartwig
| Date of birth | 23 December 1968 in Hemer (Germany) |
| 1989 - 1995 | Economic Science at the Ruhr University Bochum, Germany; Qualification: Graduate in Economics (Diplom-Ökonom) |
| 1995 - 1999 | o.tel.o, from 1997 Head of Planning |
| 1999 - 2001 | Dolphin Telecom Deutschland GmbH, Head of Controlling |
| 2001 - 2006 | Dolphin Telecom Deutschland GmbH, Commercial Director |
| since 2006 | MATERNA GmbH, Chief Financial Officer (CFO) and Managing Director |
Ralph Hartwig draws on over ten years of experience in leading positions in the field of finance: he was the commercial director at Dolphin Telecom Deutschland GmbH, operator of an analogue wireless network in Cologne. He had previously been head of controlling in the same company. Before that he was at o.tel.o and as head of planning he was responsible for the group's financial planning. He graduated from the Ruhr University Bochum, Germany, in economic science.
