LAWRENCE HURLEY U.S. Supreme Court justices have appeared wary of barring lawsuits against American companies over alleged human rights abuses abroad but signalled they could toss out a case accusing Cargill Inc and a Nestle SA subsidiary of knowingly helping perpetuate slavery at Ivory Coast cocoa farms. The two companies are asking the nine justices to reverse a lower court ruling that allowed the lawsuit, brought on behalf of former child slaves from Mali who worked at the farms, filed against them in 2005 to proceed. The case concerns a 1789 U.S. law called the Alien Tort Statute that lets…