France is closing its military bases in Senegal and will pull out all but 300 of its 1,200 troops based there.
The French embassy in Dakar said the remaining troops will run a military West African co-operation centre.
Critics have seen the presence of former colonial troops as a sign of continued French domination since independence in 1960.
France has two other major bases in Africa - one in Djibouti and one in Gabon - which will remain operational.
A spokesman for the Senegalese president said France remained an ally and strategic partner for the West African nation.
The BBC's Tidiane Sy says there will be a ceremony on Wednesday with senior army officers present from both sides to see the lowering of the French flag.
Our reporter says it will mark a new era, but is not a complete end of French military presence.
The remaining 300 troops will launch a collective security system for African military forces and continue training commitments in the region.