Always keep the source-language abbreviation 22:40 May 2, 2010
When it comes to corporate forms, there are no exact equivalents across national borders. An SA in France is only somewhat like a plc in the UK -- it is not the same in all relevant respects.
Lawyers will want to know what the thing is, not what the translator thinks is an appropriate cultural equivalent for some jurisdiction. So keep 'SARL' and, if you wish, *in parentheses, in lower case*, give an explanation such as '(private company)'. With share capital of €X.
Frankly, the limited-liability part goes without saying in the English near-equivalents; the only reason to mention it here is that it's part of the French term, and that isn't a very good reason. A more relevant characteristic of a Sarl, not explicit in its name, is that it's a *commercial* company. | 
peer agreement (net): +2