Young Finnish defender Henri Toivomaki has signed with Ajax until the summer of 2013, with the option for another two seasons.
The highly-rated 19-year-old, who has impressed while on trial at the Amsterdam club, will start life at Ajax in the reserves but is expected to make a quick transition into the first team.
Toivomaki, who can play at centre-half and right-back, joins the Eredivisie giants from native club FC Lahti.
The youngster, reportedly a target of Inter Milan and Atalanta, has been capped for his country at both Under 18 and Under 21 level.
Meanwhile, Egyptian forward Mido has departed Ajax after just four months at the club.
The former Tottenham and Middlesbrough man only arrived at the Dutch outfit last summer but has found first-team action limited, making just six appearances.
Ajax officials are understood to have approved the 27-year-old's request to leave.