Dow Chemical agrees to buy Rohm and Haas

Dow Chemical says it has agreed to buy specialty chemicals maker Rohm and Haas for $78 per share, or more than $15 billion.

Based on the per-share purchase price and the roughly 196 million shares Rohm and Haas had outstanding as of April 22, the deal would be worth about $15.29 billion.

Dow Chemical Co. values the deal at $18.8 billion including debt.

The …