12.1 Is the company a parent or a subsidiary company?
12.2 Is the parent a U.K. or foreign-owned?
Most publicly traded firms are parent companies. If your target firm does have a parent company, you will find that information in the Annual Return available from Companies House WebCHeck and the company web site. Parent companies typically own a significant amount of stock and/or have representatives on the Board of Directors.
Dunn and Bradstreet Million Dollar Directory (fee-based) provides excellent corporate trees that include the parent company and subsidiaries.
UMass Resources (for UMass students only)
Dunn and Bradstreet Million Dollar Directory accessible through Mergent Intellect provide excellent corporate trees than include the parent company and subsidiaries.