DES MOINES, Iowa (AP) — An Iowa based ready-mix concrete company has pleaded guilty to participating in a price-fixing scheme for the sale of ready-mix concrete.

The U.S. Department of Justice says Rock Valley-based Tri-State Ready Mix Inc. pleaded guilty Monday to one count of conspiring with another company to fix prices for ready-mix concrete.

Court documents show Tri-State Ready Mix President Chad Van Zee conspired with Steven VandeBrake of GCC Alliance Concrete, of Orange City, regarding prices for ready-mix concrete sold in Iowa.

Tri-State faces a fine of up to $100 million.

VandeBrake pleaded guilty in February and was sentenced to four years in prison and fined more than $829,000.

Van Zee is scheduled to be sentenced Tuesday.

Presidents of two other concrete companies also pleaded guilty in the case.