In one of the world's worst disasters at the Bhopal plant, formerly owned and operated by Union Carbide India Limited, an entity once owned by UCC, leaked poisonous gases killed an estimated 22,000 people in the December 1984 accident.

In his ruling Wednesday, US district Court Judge John F. Keenan concluded that -- even when viewing the evidence in the most favourable light for the plaintiffs -- UCC is not directly liable, nor liable as an agent of Union Carbide India Limited (UCIL), nor liable under a veil-piercing analysis.