Question: Which city are the headquarters of this airline founded in 1946 and privatized in 1969, which operates joint ventures with Delta Air Lines, located? 
Sentence (from "Delta TechOps"): With more than 9,600 Technical Operations employees and 51 maintenance stations worldwide, Delta TechOps is a full-service maintenance provider for the more than 750 aircraft that make up the Delta Air Lines fleet.
Relevant evidence: No