Undated (AP) _ American Cyanamid Co. reported record second-quarter earnings and sales Thursday and Pfizer Inc. reported a strong earnings gain, but Dow Chemical Co. announced a 36 percent earnings drop, blaming the economy and Gulf War. American Cyanamid Co.

The Wayne, N.J. specialty chemicals manufacturer earned $132 million or $1.41 a share for the three months ended June 30, up 18 percent from $111 million or $1.16 a share reported a year earlier. Quarterly sales totaled $1.42 billion vs. $1.23 billion, up 16 percent.

George J. Sella Jr., chairman and chief executive officer, said the performance reflected strong growth in the company's medical and agricultural- related businesses, but results in the chemicals business was about the same as a year earlier.

In addition, Sella said, he anticipated the company's earnings in the second half of the year would be adversely affected by less favorable exchange rates for the dollar vs. European currencies. The dollar's rising value makes repatriated profits in foreign currencies worth less.

For the six months, the company earned $237 million or $2.53 a share, up 17 percent from $202 million or $2.11 a share a year earlier. Six-month sales totaled $2.73 billion vs. $2.38 billion, up 15 percent. Pfizer Inc.

The New York-based health-care and specialty chemical company earned $179.1 million or 53 cents a share in the quarter, up 18 percent from $151.2 million or 45 cents a share earned a year earlier. Quarterly sales totaled $1.63 billion vs. $1.50 billion, up 9 percent.

Pfizer attributed the results to sales gains in its health care, consumer products and animal health businesses. The company also said its specialty chemical and mineral segments improved profitability.

For the six months, Pfizer earned $446.5 million or $1.32 a share, up 11 percent from $403.1 million or $1.20 a share a year earlier. Half-year sales totaled $3.33 billion vs. $2.98 billion, up 12 percent. Dow Chemical Co.

The Midland, Mich.-based company said second-quarter results totaled $233 million or 86 cents a share, down from $364 million or $1.34 a share a year earlier. Sales were basically unchanged at $4.79 billion vs. $4.80 billion.

Dow blamed lower selling prices and higher manufacturing costs for the declines, a combination of the uncertainty caused by the Gulf War and ''weakening industry fundamentals.'' Pressure on prices began easing toward the end of the quarter, the company said.

For the first half of the year, Dow's earnings were down 1.8 percent to $811 million, or $2.99 a share, from $826 million, or $3.05 a share, a year earlier. Six month revenues totaled $9.74 billion vs. $4.71 billion.