Caterpillar, the world's largest construction equipment manufacturer, has asked a federal judge in Delaware to dismiss an antitrust lawsuit accusing the company of conspiring to block a competitor from entering the market for heavy construction equipment, saying there was no direct evidence to support the claims.

In a brief filed Tuesday in Delaware federal court, lawyers for Caterpillar Inc. said the four-year-old suit from International Construction Products had failed to make any specific allegations linking the Illinois-based manufacturer of construction and mining machinery to an alleged plot to suppress competition and fix prices.

The filing wrapped up briefing on a bid by Peoria, Illinois-based Caterpillar and other firms to dismiss the suit with prejudice. A decision by U.S. District Judge Richard G. Andrews of the District of Delaware is expected in the coming weeks.

ICP, a North Carolina-based firm that imports and sells heavy construction equipment to the U.S., first filed its complaint in 2015, alleging that Caterpillar had used its heft in the industry to pressure an online seller to stop competitors from seller their products at lower prices.

In court documents, ICP said Caterpillar had threatened to boycott IronPlanet, an online marketplace for selling used heavy construction equipment, if IronPlanet didn't stop selling ICP's products. Caterpillar then tried to shore up the supposed scheme, ICP claimed, by merging IronPlanet and Cat Auction Services, which is controlled by Caterpillar and its equipment dealers.

Caterpillar has denied issuing a threat to IronPlanet, and it has said in court filings that ICP could point to no evidence showing any kind of agreement between with other firms regarding ICP. To the extent that Caterpillar had interacted with IronPlanet or its co-defendants, the communications were “utterly benign,” given its longstanding business relationships.

“Although discovery does not show a threat by Caterpillar, assuming it did threaten to stop doing business with IronPlanet, as alleged, that would have been a logical consideration for any business deciding how best to distribute its products,” Caterpillar's Baker & Hostetler and Potter Anderson & Corroon attorneys said in December.

ICP responded last week that limited discovery in the case had turned up evidence that IronPlanet took as a threat statements by Caterpillar and its dealers that they planned to withhold used equipment from IronPlanet if it continued its relationship with ICP. The company has said full fact discovery should be allowed to continue in the case.

On Tuesday, Caterpillar continued to attack ICP's pleading, saying the allegations did not specify between the acts of various defendants in the case and simply sought to “lump all of them together.”

Caterpillar's co-defendants Associated Auction Services, Ziegler Inc., Thompson Tractor Company Inc. and Komatsu America Corp. have all moved to dismiss the complaint on similar grounds.

ICP is represented by Boies Schiller Flexner in Washington, D.C., and Shaw Keller in Wilmington.

The case is captioned International Construction Products v. Caterpillar.