I searched a little with Google and it seems the abbreviation for a form of company, it is listed as S.C.A. near names of other consortiums and companies, often followed by R.L.
According to my understanding and a little of my knowledge it should stand for:
Società Consortile in Accomandità... a Responsabilità Limitata
A "società in accomandità" is a company where there are partners with different liability, but this is a simplistic description and business is a complex matter, even in Italy.
I don't know to which English form of company it corresponds.
Maybe your context could help to clarify if it is the form of the company or not while this italian site http://www.societaeimpresa.com/ could help you too as well as Wikipedia (a more easy reading if you're not very familiar with italian) about forms of company.