Caterpillar Inc (CAT  ) shares are tumbling Wednesday as farm equipment stocks drop after federal regulators opened an inquiry into how the industry operates.

Caterpillar Slips As Farm Equipment Stocks Fall On Federal Inquiry

Farm equipment stocks are sliding Wednesday after the Federal Trade Commission and the U.S. Department of Agriculture issued a joint request for information. The notice seeks public comment on how agricultural equipment is made and distributed. The agencies opened an inquiry into problems in those markets, including possible anticompetitive behavior. Investors may worry that the move signals more government intervention to come.

The announcement names Deere & Company but not Caterpillar. Caterpillar's drop may reflect sympathy with the group.

FTC and USDA Inquiry Builds On Deere and Corteva Settlements

The inquiry fits the FTC's continuing effort to keep farm markets competitive. The agency recently settled a case against Corteva Inc., with twelve states joining. The deal bars the company's alleged efforts to limit competition in pesticides markets. The FTC also settled an antitrust case over repair restrictions that farm equipment maker Deere & Company imposed, with five states joining. Under that settlement, farmers can fix their own John Deere tractors and other machines.

The USDA says complaints are climbing. Farmers report more obstacles to buying equipment and getting the services that keep it running. The joint request targets those complaints.

CAT Price Action: Caterpillar shares were down 6.04% at $811.37 at the time of publication on Wednesday, according to Benzinga Pro.