The 49-year-old Bosz joins from Heracles Almelo, who had resisted Vitesse's overtures in recent weeks until the payment of compensation for the highly rated coach, media reports said.
Details of his new contract would be revealed at a media briefing on Thursday, Vitesse said on their website.
Bosz, who played at Feyenoord and also had spells in France, Germany and Japan, replaces Fred Rutten at Vitesse, who finished fourth in the Dutch championship last season and will compete in the Europa League in the new campaign.
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