Shell Chemical LP, ConocoPhillipsCo. (NYSE: COP) and Marathon Petroleum Co LP won dismissal of a lawsuit claiming they unknowingly bought stolen natural-gas condensate from a smuggling ring that Mexico’s national oil company has been unable to stop on its side of the border.

Pemex Exploracion y Produccion, the state oil company’s exploration unit, brought several lawsuits against U.S. refiners in Houston federal court, claiming they facilitated a black market in NGL, even if the companies didn’t know they were buying from thieves.

Pemex said armed bandits have stolen more than $300 million in condensate from the Burgos Field in northern Mexico since 2006, trucking much of it across the border in hijacked tankers. The smugglers have eluded Mexican army helicopters and troops summoned to defend the oil fields, according to court papers.

U.S. District Judge Simeon Lake in Houston ruled May 30 that the refiners’ purchases of allegedly stolen NGL occurred more than two years before Pemex sued, which placed the transactions outside of Texas’s two-year statute of limitations on the sale of stolen property.

Mark Maney, Pemex’s attorney, declined to comment on the decision, as did ConocoPhillips’ spokeswoman Davy Kong. Shell spokeswoman Maggie Hopkins and Stephanie Griffith, Marathon’s spokeswoman, didn’t immediately return telephone messages seeking comment on the ruling.

Pemex had urged Lake to disregard the statute of limitations, arguing that applying it could turn Texas into an international marketplace where stolen property could be freely sold after a two-year waiting period.

Lake granted summary judgment to the refiners anyway, ruling that even if Pemex hadn’t waited so long to sue in the U.S., the oil company couldn’t trace specific batches of product stolen in Mexico to particular shipments purchased by the U.S. companies.

Lake granted summary judgment May 9 to BASF Corp. for the same reasons in a related Pemex lawsuit involving stolen Mexican condensate. The new case is Pemex v. Murphy Energy Corp. et al, 4:12-01081, U.S. District Court, Southern District of Texas (Houston).