    Sentence 1: When was the FCC's sixth  report and order released?    Sentence 2: To comply with FCC  ownership restrictions in effect at the  time that barred common ownership of  two television stations in the same  market, UPT sold its Chicago television  station, WBKB-TV, to CBS (which  subsequently changed the station's call  letters t0 WBBM-TV) for $6 million,  while it kept ABC's existing Chicago  station, WENR-TV.