Sartor, 26, has been linked with numerous club over the past few months, including Chelsea, West Ham and Rangers, however the Italian defender has opted to remain in Italy.
It is believed that no transfer fee has been involved in the trade and that it is just a straight player exchange.
Siviglia only joined Roma last summer from Atalanta, but found first team opportunities hard to come by under Fabio Capello making only five appearances for the giallorosso.
Roma are keen to strengthen their defence after marginally missing out on the scudetto, despite having the likes of Cafu, Walter Samuel, Vincent Candela and Christian Panucci already at the club.
