I would've heard this story if true, I reckon. I spend much of my day reading news sources looking for just this sort of thing. I think you may be referring to a story from a year back, when PSG signed their ludicrous sponsorship deal - there were stories that City would now also seek a sponsorship deal worth over £100m/season. I'm fairly sure that that story has been scotched since then though.
The new package deal bit came in a very recent NYCFC article that mentioned that they're looking at not only selling the jersey spot but will also put up that sponsor on the outfield walls surrounding the field at Yankee stadium.
Yeah. I'm pretty sure this story is dead though. Considering that City have been including Etihad board members in recent business developments where the sponsors should have no say normally, it's my opinion that the club and the airline have a private pact to grow their businesses side-by-side. I can't see City moving to a new shirt sponsor.