Gonzalo Castro has signed a contract extension with Bayer Leverkusen, committing himself to the club until 2014.

The 23-year-old, capped five times by Germany, has made 149 Bundesliga appearances for Leverkusen, scoring seven goal.

"Gonzalo Castro is an important part of our future," said the club's sporting director Rudi Voller. "We're very glad that we can keep him on this long-term deal."