Huntsman Corp. of Texas and Switzerland's Clariant have agreed to an all-stock merger that would create a specialty chemicals giant valued at around $20 billion (including debt). Clariant shareholders would hold around a 52% stake in the combined company, which is expected to generate $13.2 billion in annual sales and $2.3 billion of EBITDA.

Why it's a big deal: This tie-up is part of a trend of cross-border consolidation in the mega-chemicals space, following the pending deal between Praxair (Connecticut) and Linde (Germany) and PPG Industries (Pittsburgh) attempting to purchase Dutch rival Akzo Nobel. It's also notable for private equity buffs (yes, such people exist), as Huntsman was at the center of what arguably was the most contentious M&A failure failure of the financial crisis era.

Fun fact: "Huntsman... is best known for inventing the clam-shell styrofoam box for McDonald's Big Mac burgers." ― Reuters