Katzkin Leather Inc., the nation's largest manufacturer of leather interior upgrades for the automotive aftermarket, is suing Nissan North America Inc. in federal court.

The suit alleges Nissan claims there's an increased liability exposure for dealerships that install or facilitate the installation of aftermarket leather interiors in vehicles equipped with occupant detection systems containing sensors that can tell if a passenger seat is occupied. It is part of a vehicle's airbag system.

All new vehicles will contain such sensors by September of 2006. The lawsuit alleges that Nissan is making such claims to promote sales of its own leather interiors over those Katzkin's.