A couple of sitcoms have switched channels in past (as chip says, Men Behaving Badly is probably the most high profile example), but there's no getting away from the fact that Not Going Out is pretty expensive to produce compared to some other sitcoms, so it would be hard to transfer.
Here's a quote from someone in TV I know (who doesn't want to be named). They think NGO has been axed for political reasons:
This is the BBC's way of saying to the big comedy indies like Avalon and Open Mike/Off The Kerb that they can no longer dictate terms. NGO costs a lot because Avalon have been charging top whack for years - because they control so much talent. In these crunching times, all it needs is one relatively big player to 'fail' - and they can use that to show who's boss. I don't know who makes Life Of Riley but I bet they get a fraction of what Avalon got for NGO.