Czech Republic defender Tomas Sivok signed a four-year contract with Turkey's Besiktas.
The 24-year-old Sivok was previously on loan from Serie A club Udinese to Sparta Prague. The Czech club announced the move Saturday.
Sivok, who can also be used as a midfielder, has played six internationals and is in the Czech squad for next week's European Championship.
Sivok moved to Udinese in January 2007 on a a 4 1/2-year contract but failed to get a spot in the starting lineup.
