Do we have access to any large databases of privately held companies in specific industries?
The online directories we use for private companies are Reference USA, and Lexis-Nexis Company Dossier. Each of these databases supports searching by industry codes (SIC or NAICS). The information available about privately held companies in the United States is rather limited. Typically you can find name, address, key personnel, perhaps establishment date, total sales or revenue, and maybe accounting firm and number of people employed.