New regulations more notable for what they retain than what they change.

Key Points:

..The US anti-inversion rules have more than a 15-year history of impacting the structure and practicality of certain cross-border deals, including mergers, acquisitions, and spin-offs.

..The recently issued regulations represent the latest in the series of statutory and regulatory developments, which will no doubt continue to shape the current M&A market.

..The developments are particularly important when combined with the significant changes in the US tax regime brought about by recent US tax reform.