Grains closed mixed on the Chicago Board of Trade Thursday as continued declines in global stock markets exacerbated fears of an economic slowdown.

Corn was off 29 3/4 to off 30, soybeans were off 49 to off 50 1/4, wheat was off 33 3/4 to off 35 1/2 and oats were off 11 1/2.

Corn closed lower with the year's sales at 26.6 percent of U.S. Department of Agriculture's expectations against a five-year average of 27.7 percent. Wheat prices fell as beneficial rain fell on Argentina's wheat belt. Soybeans declined as most U.S growing areas reported frost conditions have not yet arrived.

The prices:

Corn: Dec 4.54, off 30; Mar 4.73, off 30; May 4.85, off 30; Jul 4.96, off 29 3/4.

Soybeans: Nov 10.04, off 49; Jan 10.20 3/4, off 49 3/4; Mar 10.35 3/4, off 50 1/4, May 10.47, off 50.

Wheat: Dec 6.36, off 33 3/4; Mar 6.57 3/4, off 34; May 6.71 3/4, off 34 1/2; Jul 6.84 1/4, off 35 1/2.

Oats: Dec 3.10, off 11 1/2; Mar 3.27 1/4, off 11 1/2; May 3.39, off 11 1/2; Jul 3.50 1/2, off 11 1/2.