There is no source that provides exhaustive lists of companies in a particular sector. This is especially true for companies that are small or secretive or are new startups. Build company lists by searching company databases by NAICS or other industry codes - supplement your results list with a search by business description keywords.
Mint Global contains information on over 200 million companies worldwide, both private and public. It's the Orbis database with a streamlined interface.
"Mint Global includes companies' financial accounts, credit scores from a number of independent providers, directorships, ownership structures, PEPs and sanctions information, and details of mergers and acquisitions activity.
The same data is accessible with an expanded interface via Orbis. "
Detailed company information for public companies. The Research tab links to investment analyst reports for companies. Click on the Advanced Research link on the Research page to search across all analyst reports for keywords like "pipeline" or for company name or product or industry. Default search is the last 90 days, which can be changed to get longer date ranges. For startups and private companies that are venture capital or private equity funded, go to the Screening and Analysis tab --> Private Equity --> Company or Investors.
Thomson ONE is a platform for public company financials and analyst research, as well as venture capital firm, fund, and portfolio company information. This resource replaces both Investext and VentureXpert. Note: Works only with Internet Explorer.