The veteran sitcom, which was recently moved to a new slot on Thursdays at 8.30pm, will not return for a seventh season, according to TV Series Finale.
The site claims that the sitcom's cast and crew are currently filming the last two episodes for season six, which will serve as the final episodes for the show.
Cast members - including David Spade, Patrick Warburton, Bianca Kajlich, Megyn Price and Oliver Hudson - were apparently informed of the network's decision on Friday night.
TV Series Finale credits an unnamed source as saying: "The reality is it's got to be politics. The network has always had it out for [series creator] Tom [Hertz] and the show.
"It really does seem to be a desperation move on their part to find something that hits it out of the ballpark in that Thursday 8.30 slot."
Warburton previously criticised CBS, after the network originally planned to air Rules in a "s**t" Saturday night slot.
"The scripts are great and we're having a lot of fun doing the show," he said. "But God knows if anybody's gonna find us on Saturday night."
> Rules of Engagement premiere delayed by two weeks
> How to Be a Gentleman, Rules of Engagement swapped over by CBS
Watch a trailer for Rules of Engagement below: