On December 31, 2003, Quorum Broadcasting, owner of CBS affiliate KOLR, merged with Nexstar; as the Springfield market did not have enough television stations to permit a legal duopoly, KOLR was instead sold to Brecksville, Ohio-based Mission Broadcasting. This arrangement placed KDEB-TV in the unusual position of being the senior partner as a Fox-affiliated station in a virtual duopoly with a CBS affiliate (most virtual or legal duopolies involving a Fox affiliate and a Big Three-affiliated station result in the Fox affiliate serving as the junior partner); from September 2011 (when channel 27 lost its Fox affiliation) to September 2014 (when it joined MyNetworkTV) it was the only duopoly (virtual or legal) in existence involving a "Big Three" station in which an independent station serves as the senior partner. The station changed its call letters to KSFX-TV in 2005.