CHICAGO, Dec. 23 (UPI) -- Grain futures closed mostly higher Thursday with wheat prices flat after a sharp run up on Wednesday.

Corn was up 4 1/2 to up 5 1/4, soybeans were up 20 1/4 to up 20 3/4, wheat was off 1/2 to up 1/2 and oats up 1 3/4 to up 3.

Corn prices made modest gains with the dollar index off 0.33 percent. An Iraqi purchase of 100,000 metric tons of wheat and Algeria's purchase of 200,000 metric tons lent support to wheat prices. Soybean futures surged with high export demand, including a U.S. Department of Agriculture announcement of 150,000 metric tons to an unnamed buyer.

The prices:

Corn: Mar 6.14 up 5, May 6.22 up 5, Jly 6.25 3/4 up 4 1/2, Sep 5.78 1/2 up 5 1/4.

Soybeans: Jan 13.49 1/2 up 20 3/4, Mar 13.60 up 20 1/4, May 13.67 up 20 1/4, Jly 13.69 1/4 up 20 1/4.

Wheat: Mar 7.83 up 1/2, May 8.10 1/4 up 1/2, Jly 8.23 off 1/2, Sep 8.36 3/4 up 1/2.

Oats: Mar 3.93 1/2 up 1 3/4, May 3.98 1/2 up 3, Jly 3.99 1/2 up 3, Sep 3.54 1/2 up 3.