Continental companies are translated as S.A.
So a when a Greek company is translated into UK/US English it is always S.A. A note here, a Greek ΑΕ (S.A.) is never translated into English as "Anonymous Society" (it sounds like a twelve-step group, i.e. Alcoholics Anonymous or the anonymity in contemporary society) but as Société Anonyme (accents included). Funnily enough, I have seen the term "Anonymous Society" in the English page of a very well known Greek translation agency amongst many other places! A web search will convince you. Look also at the last paragraph of this post.
UK companies (as you correctly remarked) as PLC in English (Public Limited Company or Ltd (Limited). Cypriot companies seem to follow the same rules. Correct me if I am wrong.
US companies usually as Inc. (Incorporated).
Useful info
What do .GMBH, .INC, .LLC, .LLP, .LTD, and .SOC stand for?
GMBH: Gesellschaft mit beschränkter Haftung. Translates to "Company with limited liability." It is widely recognized and used in Austria, Germany, and Switzerland.
INC: Incorporated. Means a company is Incorporated, and the owners have limited liability. It is widely recognized and used in USA.
LLC: Limited Liability Company. An LLC has limited liability, and unlimited life. It is widely recognized and used in USA.
LLP: Limited Liability Partnership. It is widely recognized and used in USA.
LTD: Limited. Indicates that a company is incorporated and that the owners have limited liability. It is widely used in the UK and many former British colonies, as well in other countries such as Japan. This can also be used in the USA.
SOC: Sociedad Anonima Translates to "Anonymous Society" and is the equivalent of SA which is a limited partnership with shares. It is widely recognized and used as: Societe Anonyme (Belgium, France, Greece, Ivory Coast, Luxembourg, Morocco), Sociedades Anonimas (Brazil), Societa in Accomandita per azioni (Italy), Sociedad Anonima (Me xico, Portugal), Spolka Akcyjna (Poland), Societate pe Actiuni (Romania).