The deal terms come from a person who wasn't authorized to speak publicly and who spoke on condition of anonymity.
CBS said the channel, available in more than 80 million homes, will continue to focus on entertainment. Details about rebranding it will come. It will combine CBS' programming, production and marketing with Lions Gate's resources in movies, TV shows and digital content.
Previously, the channel had mainly been used as a guide for other channels, but set-top boxes come with their own guides these days. The channel, called TVGN, currently shows reruns of such programs as "Who's The Boss," ''Ugly Betty" and older movies. Most viewers don't see the scrolling TV listings guide any more.
TV Guide magazine, which is owned separately by OpenGate Capital, isn't part of the deal.
Analysts have said the channel will benefit from CBS's operational and TV programming expertise. Aside from the CBS network itself, it will become the most widely distributed channel that CBS operates. CBS also owns the Smithsonian Networks, CBS Sports network and premium channel Showtime.
CBS Chief Executive Les Moonves said in a statement the channel will offer a strategic way for CBS to use its brands "and gain access to a highly distributed basic cable network that has a lot of upside."
CBS and Lions Gate have worked together in the past. Lions Gate produces the shows "Weeds" and "Nurse Jackie" for Showtime.
CBS shares were up 4 cents in after-hours trading at $45.75 following the announcement, after closing up 29 cents at $45.71 in normal trading. Lions Gate shares rose 19 cents to $24, after rising 2.7 percent to close at $23.81 in the regular session.