Carbo Ceramics Inc., the largest supplier of man-made proppants for the oil and natural gas industry, said sales of its synthetic fracking material fell as customers used more sand, Bloomberg said Sept. 22.

Third-quarter sales of ceramic proppant will fall 18% from the prior quarter, matching first-quarter levels, the Houston-based company said Sept. 22 in a statement. The company reported sales of 454 million pounds in the second quarter.

“We plan to manage the current competitive pricing environment, caused by proppant oversupply, by focusing on sales volumes and introducing new technologies,” CEO Gary Kolstad said in a Sept. 22 statement.

The announcement was made before regular trading began in New York. Carbo had dropped 27% this year as of the close of trading Sept. 19.

The company reported selling 534 million pounds of ceramic proppant in the 2013 third quarter.