Researching industries that are dominated by private companies can be more difficult than those dominated by public companies. Unlike the public sector, private companies are not required to disclose their company financials, annual reports, employee information, and do not have to file with the SEC.
For more information see the Library of Congresses guide on Researching Private Companies and this SEC explanation of public companies that turn private.
Definition of CI: the process of monitoring the competitive environment and analyzing the findings in the context of internal issues, for the purpose of decision support. CI enables senior managers in companies of all sizes to make more-informed decisions about everything from marketing, R&D, and investing tactics to long-term business strategies. (From Strategic and Competitive Intelligence Professionals Basic FAQs)
Full-text news (including broadcast transcripts), business, legal, and reference information. Useful for finding full-text of current performing arts and media industry news in major newspapers. Includes biographical information from Who's Who titles. Formerly LexisNexis Academic.
Due to not being publicly traded, private companies have fewer requirements for reporting financial and other information. Please see the list of databases above. Some general information, such as location of incorporation, board composition, etc. can be found in databases like Mergent Online and/or AtoZdatabases: Target Company Lists, which include the ability to search by location. You may also be able to find information about some companies by searching for them by name (try searching with and without quotes around the company name) or by name of known executives, in news and press releases, which can be found in Nexis Uni and/or Business Source Complete. You can also find industry reports from databases like IBISWorld, which often include names of major public companies in a sector, which can be beneficial for comparison. Sort by annual income and other fields in Mergent Online to find public companies comparable to the size of the private company you wish to research.
[f] = individual firm or company