When an in-house counsel in England visits a corporate subsidiary in Germany, the counsel generally is allowed to give legal advice and practice law under European Union rules. But if an in-house counsel at, say, General Motors in Detroit wants to visit a plant across the state line in Ohio, he isn’t allowed to offer legal advice there under U.S. rules.

The general counsel could give the same legal advice over the phone or send it by e-mail from Detroit, but once he steps into Ohio he is no longer authorized to practice law. That’s one of several regulatory dilemmas that plague general counsel of transnational and global companies, according to law professor Carol Silver of Indiana University’s Maurer School of Law in Bloomington.