It's hard to answer since you didn't clearly define either Satanism or "organized religion".
Under the most common understanding, Satanism didn't become an organized "religion" till The Church of Satan was established as an organization according to The Satanic Bible, written in 1969 by Anton Szandor LaVey. There seems to be no basis to attribute this to the Catholic Church.
It was preceded by a number of cults that were Satanist, but that were not major enough to be labeled as an "organized religion" - e.g. "Ophite Cultus Satanas" in 1940s.
There were Satanic cults/worshipers earlier in history, but again, none really fit the "organized religion" qualification.
However, what may have influenced the rumor that you heard, were two facts:
Catholic Church DID accuse certain groups/people of being "Satanist", despite the fact that they were not, in fact, Satanist in their nature (e.g. worshiping a rebellious theistic figure related to Judeo-Christian religious beliefs). This is due to the fact that a monotheistic religion would understandably relegate any other-deity worship to be worshipping the opposite of that religion's god, which in the case of Christians was Satan).
Catholic Church would take individual people who did things that may be considered Satanism (e.g. serve Black Mass etc...) and them lump in with a bunch of other people who had nothing to do with Satanism - sometimes for political reasons, sometimes related to the previous bullet point of just calling all non-Christians "Satanist" by their definition.
For example, pretty much any pagans were designated as "Satanist" by Christianity, despite the fact that they didn't fit the above definition by any stretch of the imagination. It was basically an alternate definition made up by the Church of "if you worship any deity aside from the God of the Christian Bible, you are automatically considered to be worshiping Satan".
Same goes for witches - while they were universally accused by the Church of things like worshipping Satan and Black Masses, it's very doubtful that most were.
Early Gnostic sects could also be called Satanist without actually worshiping Satan - many of them would probably fit the paganism catch-all listed above. A good example would be Borborites.
