By David Shepardson, Ben Klayman WASHINGTON/DETROIT (Reuters) -Chrysler parent Stellantis said on Monday it has filed eight additional lawsuits against the United Auto Workers and 23 local units, saying the union has violated its contract by threatening to strike over the company's delays in planned investments.

Stellantis NV said Monday it filed nine federal lawsuits against the United Auto Workers and two dozen union locals late last week it tries to prevent the union from calling a mid-contract strike over its delays reopening an Illinois assembly plant.

Stellantis denies breaking the terms of the labor contract it signed with the United Auto Workers union only a year ago.