Indeed, as are Omersub and Technisub, which I hadn't mentioned either.
I only had time to list a few Italian manufacturers when I posted my
message yesterday. Since then I've found a list of diving equipment
companies posted by the Italian diving magazine "Mondo Sommerso" at:

http://www.mondosommerso-online.it/attrezzature/aziende.htm

Be aware, though, that not all these firms manufacture diving
equipment. Some will simply distribute the products of other companies.
In the global marketplace of nowadays, where there are worldwide
branches and mergers, it's becoming increasingly difficult to tie a
company to a particular country.