He was the chief financial officer in Oslo municipality in the late 1980s. He resigned in March 1990. From 1996 to 1997 he was an acting chief executive at
Ullevål Hospital. He also chaired
Aker Hospital from 1994 to August 2000. In October 2000 he was named as chairman of Ullevål Hospital. He was also leased by
Dagsavisen in 2001 to save the newspaper's economy. He has performed the same task in several other newspaper such as
Østlendingen,
Hamar Arbeiderblad,
Ringsaker Blad and
Moss Dagblad, the book club
De norske Bokklubbene, the publishing houses
Aschehoug and
Universitetsforlaget. He was hired by Bærum municipality in 2004 to help them cut up to 80 million off the health budget, then in Drammen municipality in mid-2005 to clean up their care services. From 2005 to 2008 he chaired several
health trusts in South and Eastern Norway;
Rikshospitalet-
Radiumhospitalet and
Sørlandet Hospital. A dispute in 2008 on whether to construct a new patient hotel at Radiumhospitalet led to Pettersen's resignation. Briefly in 2005 he was also a board member of Achima Helse, a company that leased workers to the same hospitals. From 2008 to 2009 he was instead brought in as acting director of the
National Museum of Art, Architecture and Design. From March 2009 to August 2010 he went on to serve as acting director of
Stavanger University Hospital. He returned to the administrative officer staff of Drammen municipality. In late 2011 he was hired by the
University of Oslo. ==References==