The versatile Czech Republic international will continue his career in Turkey after the club managed to ward off interest by awarding him a new three-year contract
The Czech Republic international's present agreement was due to expire at the end of the 2012-13 season, having signed a four-year deal with the Turkish side upon his arrival in 2008 with the option of a fifth.
Reports last month had linked Sivok with a move to Spanish outfit Sevilla, while Premier League sides Everton and Fulham were also rumoured to be interested in securing his signature, having risen to prominence for his country at Euro 2012.
He will earn now €1.2 million for the 2012-13 season and receive a pay rise of €100,000 in each of the next two years. He will also win further bonuses depending on the number of games he plays for Besiktas during the upcoming campaign.