The suffix of a company limited by shares is s/a-the complete spelling is Sociedade An? Nima If you don't write a suffix, you can use the prefix Cia, which is Companhia.
What I said above is that according to the Brazilian Civil Code, I don't know about other Portuguese-speaking countries.
In Brazil, there are many differences between limited companies and joint-stock companies, and some laws and regulations are different.