NEW YORK (AP) — The collapse of a major joint venture between Dow Chemical and a state-owned Kuwaiti company raised questions yesterday about Dow's continued willingness to pay $15.3 billion for Rohm & Haas Co.

The shares of both US companies plunged more than 17 percent in midday trading.

Dow agreed to pay a 74 percent premium for the Philadelphia-based specialty chemical maker during the height of the energy crises in July, when the company was burdened by unprecedented costs for energy and carbon-based feedstocks.

One major deal in the chemical sector, Hexion's $6.5 billion bid for Huntsman Corp., has already unraveled.

Kuwait's government on Sunday scrapped its planned $17.4 billion K-Dow joint venture, calling the deal "very risky" amid a global financial crisis and because crude prices have tumbled more than 70 percent since the agreement was announced.

Dow had expected to get as much $9 billion in pretax proceeds from the deal.

Dow officials would not comment and it remained unclear yesterday if the world's second-largest chemical company intended to scuttle the agreement.

Rohm & Haas said it "continues to work diligently" to complete the acquisition, which it said was not affected by the K-Dow venture.

Some analysts believe it would be unrealistic to expect the same price, however.