CBS claimed victory on Tuesday in the key November television sweeps period, but Fox said it was the only broadcast network to show year-on-year gains in both total viewers and the 18-49 year-old age group coveted by advertisers.
CBS Corp's CBS broadcast network said it had the highest number of total viewers in the closely watched four-week period for the ninth consecutive year, with an average 11.3 million total viewers tuning in for each show.
Ratings measured in the November sweeps are important because they are used to set local TV advertising rates for future months.
Rival network ABC, a unit of the Walt Disney Corp, finished No. 2 in total viewers with an average audience of 10.5 million, and General Electric Co's NBC is expected to report on Wednesday when final figures from industry tracker Nielsen are available.
News Corp's Fox, which traditionally sees its strength in January with its twice weekly American Idol broadcasts, said it had won the 18-49 age group in November for the first time in its history, beating second-placed ABC by 13 percent. Excluding sports programs, ABC said it would have claimed the No. 1 spot in that key group.
Fox said it increased its average total viewers during the sweep by 29 percent over the same period last year.
Fox was helped by the strength of World Series baseball and new shows like high-school choir comedy Glee and its Sunday animated series The Cleveland Show.
Although Glee, with about 7 million viewers per week, is not among the Top 20 most-watched shows, Fox said it was bringing in 45 percent more viewers to the 9 p.m. Wednesday slot than last year.
For CBS, its crime franchises CSI and NCIS, which have spinoff versions set in Miami and Los Angeles, are consistently among the top 10 dramas on network TV, while its The Big Bang Theory and Two and a Half Men are two of the highest rated comedies.