l Dow Chemical Co., the biggest U.S. chemical maker, agreed to buy Rohm & Haas Co. for about $18.8 billion, reducing its dependence on petroleum-based commodity chemicals and increasing sales of more profitable products. Rohm & Haas investors will receive $78 in cash for each share they hold. Financing includes equity investments of $3 billion by Berkshire Hathaway Inc. and $1 billion by the Kuwait Investment Authority. Chief Executive Officer Andrew Liveris said the acquisition wil...