Using Company Symbols in Google Adwords Campaigns

The use of company symbols as keywords in the paid search of Internet search engines (here: Google AdWords) not necessarily implicates a likelihood of confusion with the protected symbol if the advertisement displayed in the section for paid search results does not actually use the protected symbol.
(Federal Court of Justice, I ZR 30/07, 22 Jan 2009)

Company symbols are protected as commercial designations under German trademark legislation, Sec. 1 (2) and Sec. 5 (1) German Trademark Act (MarkenG). In Sec. 5 (2) company symbols are characterised as signs that are used in the course of business as name (of a firm) or special designation of a business.

Unlike a trademark, a company symbol is directly linked to a company and only indirectly related to a specific product or service.