Arnold filed for divorce on Monday in Los Angeles Superior Court citing "irreconcilable differences." The actor-comedian and Roos have no children.
The couple married in 2002 and split briefly in August 2006 after Arnold filed a petition for legal separation. Six months later, Arnold asked a judge to dismiss that request while the couple attempted to work things out.
Arnold's screen credits include "True Lies."
The choice of the city of Helsinki is not incidental as the capital of Finland had hosted US-Soviet negotiations on the limitation of nuclear stockpiles in 1969