Athens has been awarded the 2006 World Cup, while Stuttgart will stage the annual World Athletics Final for the next three years.
The World Cup will take place next year on 16-17 September.
The nine teams involved are Africa, Americas, Asia, Europe, Oceania, USA, Greece and the two top teams from the 2006 European Cup (Super League).
The World Athletics Final will be held in Monte Carlo this year before moving to Stuttgart from 2006-8.
The International Association of Athletics Federations (IAAF) council made the decision at a one-day meeting in advance of their two-day biennial congress starting on Wednesday.
Helsinki is staging the 10th World Championships which open on Saturday.