Klitschko beat Samuel Peter to reclaim the WBC title in October
Vitali Klitschko will defend his WBC heavyweight title against mandatory challenger Juan Carlos Gomez in Germany in early March.
Britain's David Haye had agreed terms to fight Klitschko in London this summer but the Ukrainian has opted to face the Cuban fighter instead.
Haye is still in talks to face Klitschko's younger brother Wladimir, the IBF and WBO champion.
Wladimir has always been the preferred target for Haye.
A statement from the WBC said that Vitali Klitschko and Gomez had a reached a definitive agreement for their bout and signed for their mandatory fight.
They confirmed purse bids - which were due on Friday - were not necessary after both sides agreed terms between themselves.
"Mr Shelly Finkel, on behalf of Klitschko, and Ahmet Oener, on behalf of Gomez, directly had communication with the WBC president to provide him with such information," said the statement.
"The fight will be held in German locality, within the first two weeks of March 2009."
Talks are ongoing between Haye's camp and the Klitschkos about a fight against Wladimir. The chances of that fight happening have been boosted by reports the Ukrainian was considering facing the Londoner instead of going through with his anticipated defence against Chris Arreola.
Haye made the permanent move up to heavyweight in November with a stoppage victory over American veteran Monte Barrett in front of the watching Vitali.