Graduated from A.P Moller/Maersk's shipping school in Copenhagen in 1988. Flemming worked in Maersk Bulk and Maersk Tankers until 2000, and he had postings in New York and Oslo. Graduated with an MBA degree from Cranfield University School of Management in 2001 and subsequently he worked with Neptune Orient Lines subsidiary APL Logistics in London.
Flemming took up his present position as managing director of United Product Tankers in 2003.