(CNN) -- German champions Bayern Munich have confirmed the signing of Brazilian defender Luiz Gustavo from Bundesliga rivals Hoffenheim.
As part of the deal, which the German media have reported is worth an estimated €15 million ($20 million), Bayern's 18-year-old Austria midfielder David Alaba will move in the opposite direction on loan until the end of this season.
"Luiz Gustavo is the player we always wanted, and he's making the team stronger," Bayern chairman Karl-Heinz Rummenigge told the club's official website when the January transfer window opened on Monday.
Bayern will be hoping the new acquisition can help revive their domestic fortunes, with Louis Van Gaal's team fifth in the table and 14 points behind runaway leaders Borussia Dortmund during the winter break.
Gustavo arrived at Hoffenheim from Brazilian team Corinthians Alagoano in 2007, and was part of the side which gained promotion to German football's top tier in 2008.
He will fill the boots of Argentina's Martin Demichelis, who has completed a transfer to Spanish side Malaga after seven years with last season's UEFA Champions League runners-up.
Inter Milan, who beat Bayern in the 2010 final, have sealed the capture of Italy center-back Andrea Ranocchia from Genoa.
The 22-year-old, who made his international debut against Romania in November, has signed a contract with the Nerazzurri which will run until 2015.
France international defender Adil Rami has agreed a transfer to Spanish La Liga side Valencia.
However, the 25-year-old will remain with French Ligue 1 leaders Lille on loan until the end of this season before he moves to the Mestalla in July.
"I am happy to have made my dream of playing for one of the great European teams come true," Rami told Valencia's website.
"Valencia are well-known throughout the world and in France, so I have achieved something that all footballers aim for."