Norbert Quinkert entered Bull AG in 1965 as system analyst, later worked on IT projects as project manager before moving on to Sales in 1970. In 1973 he transferred as district manager to the Information Service arm of Bull General Electric, which later became General Electric Information-Service GmbH.
From 1978 onwards he held various positions as Sales Director, Marketing Director and finally Managing Director of the firm. In 1984 the Austrian, Swiss, Norwegian and Swedish affiliates were added. 1988 he took over GE Medical Systems Central Europe as Vice President Central European Operations. In dual role he was appointed President General Electric Deutschland, charged with overseeing GE's businesses in Germany, Austria and Switzerland.
In 1995 Norbert Quinkert joined Motorola as Chairman of Motorola GmbH and was also made responsible for Motorola's Austrian, Swiss and Dutch operations. In 2007 he changed to the board of directors of Motorola GmbH and was founder of Quinkert Herbold Fischer Executive Search GmbH
In the American Chamber of Commerce in Germany he serves as Executive Vice President.

Others:
- AMG, Advanced Metallurgy Group, Wayne Pennsylvania, member of the board
- QSC AG, Köln, member of the board
- PFW Aerospace AG, Speyer, member of the board
- WISTA Management GmbH, Berlin, chairman of the board
- VTION Wireless Technology AG, Frankfurt/Fuzhou (PRC), vice-chairman of the board
- Dresdner Bank, Frankfurt, member advisory council
- American Chamber of Commerce in Germany, Executive Vice President
- Frankfurt International School, member advisory council
- GSBA, Zurich, Switzerland (MBA School), member advisory council