The announcement was made at the Detroit auto show.
Union seeks collective bargaining rights for small group of skilled workers at Tennessee plant
Rival union wants to prevent the UAW from gaining bargaining rights for the first time.
Automaker says it needs a bigger body shop at the Tennessee plant to accommodate future production needs.
An army of robots are cutting energy use by up to 220,000 kw/h per year at the Chattanooga, Tenn. manufacturing site.
If successful, it would become the first unionized foreign auto plant in the southern US.
President Bob King says the union is stepping back because the challenge could take years to come to a conclusion.
Sen. Corker stands by claim the German automaker will expand plant is UAW loses vote.
If UAW succeeds, the Chattanooga plant would become the first among foreign automakers in the South to unionize.