OK I found it. The right form should be "ceteris paribus" : I searched in the net and I found millions of them in pages of the whole word, but also 29 "coeteres paribus"
These 29 pages are mostly in Portoguese, Catalan and some in Spanish (???)
It is a phrase used specially in contracts, meaning "if the other things remain as they are now". Is this the meaning of the Portoguese translation?
I think the Portuguese translation is good, too literal though. Apple, you're right, "ceteris paribus" is the right form. It's rather used in economics prospects than in contracts. It's very usual among Spanish and Portuguese economists, but I thought it was just universal!