Jan was formerly President and CEO at Proximus Belgacom Mobile, a joint venture between AirTouch (currently Vodafone-AirTouch) and Belgacom (the state-controlled telephone operator of Belgium), which provides mobile cellular services. He also served on the company's board from 1994 till 1998. Before his assignment in Belgium, Jan was President and CEO of AirTouch International. Under his leadership, numerous cellular service joint ventures were established in Europe and Asia (i.e., Germany, Portugal, Sweden, Spain, Italy, Belgium, Japan, and Korea) through winning government licenses or acquisition.

Representing AirTouch, Jan also served on the board of most of these ventures, the most significant being the Mannesman Mobilfunk Board in Germany. From the start of his career in 1962 until he joined AirTouch in 1986, Jan has held management positions with increasing responsibilities in the areas of engineering, marketing and sales at ITT and US Sprint with assignments in Belgium, Venezuela, Hong Kong, Indonesia and the USA.