Happened with Dow-Dupont! A three-way split, even (from a two-way merger). Took roughly two years and was the shareholders' plan from the start. By most accounts it went very smoothly.

[1] https://www.investors.dupont.com/news-and-media/press-releas...

[2] http://www.dow-dupont.com/

Progressive corporate taxation could make it happen for reasons other than dodging the ghosts of chemical sins past!