Can lawyers not admitted to practice in the United States serve as a US “general counsel”?

Don Liu, general counsel of Xerox, mentions an unusual restriction on legal departments. “I’m aware of at least two U.S. public companies that had a non-U.S. lawyer who ran their legal department, although they couldn’t call themselves the general counsel because of licensing requirements.” The quote comes from David Galbenski, Unbound: How Entrepreneurship is Dramatically Transforming Legal Services Today (2009) at 34 (See my post of March 22, 2006 that differentiates “general counsel” and “chief legal officer.”).

If “General Counsel” has professional ethics or licensing restrictions, does “Chief Legal Officer”? Do state laws prohibit people other than U.S.-admitted lawyers to carry the title “General Counsel”? By the way, I think in decades past, law firms were sometimes referred to as a company’s “general counsel.”