Fox News Channel had the most viewers, and CNN had the most viewers in the key adults 25-54 demographic when the cable news channels broke into regular coverage to cover the rebel assault into Tripoli, Libya Sunday evening.From 6 PM ET-12 AM ET, FNC averaged 950,000 total viewers, including 194,000 adults 25-54. CNN averaged 701,000 total viewers, including 246,000 A25-54 and MSNBC averaged 308,000 total viewers and 132,000 A25-54.From 8 PM ET (when MSNBC started breaking into its regular programming with updates) to 12 AM ET, FNC averaged 870,000 viewers, including 192,000 A25-54. CNN averaged 717,000 viewers, including 250,000 A25-54 and MSNBC averaged 266,000 viewers including 97,000 A25-54.FNC peaked during the 6 and 7 PM ET hours, where it averaged more than one million total viewers and around 200,000 A25-54. CNN peaked during the 10 PM hour, averaging 766,000 total viewers and 284,000 A25-54. CNN was the top-rated cable newser in both total and demo viewers from 11 PM ET-1 AM ET.MSNBC peaked during the 8 PM hour, averaging 348,000 viewers, including 102,000 A 25-54.We will have the full Sunday ratings grid up shortly.