April 18 (Reuters) - U.S. gun manufacturers on Thursday

asked the U.S. Supreme Court hear their challenge to Mexico's

$10 billion lawsuit seeking to hold them responsible for

facilitating the trafficking of firearms to violent drug cartels

across the U.S.-Mexico border.

Eight companies including Smith & Wesson Brands ( SWBI ) and

Sturm, Ruger & Co ( RGR ) in a petition argued that a lower

court wrongly concluded the case qualified for an exception to a

U.S. law that grants the firearms industry broad protection from

lawsuits over the misuse of their products.

A trial court judge had dismissed the case citing that law,

the Protection of Lawful Commerce in Arms Act. But Boston-based

1st U.S. Circuit Court of Appeals in January concluded Mexico's

claims fit within the narrow exception to the liability shield.

The 1st Circuit did so after finding that Mexico had

plausibly alleged the business practices of the seven gun makers

and one distributor it had sued aided and abetted the illegal

trafficking of guns to Mexico.

The companies on Thursday told the 6-3 conservative majority

U.S. Supreme Court that the 1st Circuit's ruling defied the high

court's past precedents and should never have been allowed to

move forward.

"Mexico's suit has no business in an American court," their

lawyers wrote.

The companies argued that absent the U.S. Supreme Court's

intervention, the U.S. firearms industry would face years of

costly litigation by a "foreign sovereign that is trying to

bully the industry into adopting a host of gun-control measures

that have been repeatedly rejected by American voters."

Alejandro Celorio, legal adviser to Mexico's foreign

ministry, wrote on the social media platform X that the county

would "follow up on this request and will be ready in case the

Supreme Court decides to admit the matter for study."

In its lawsuit filed in 2021, Mexico alleged that the

companies undermined its strict gun laws by designing, marketing

and distributing military-style assault weapons in ways they

knew would arm drug cartels, fueling murders, extortions and

kidnappings in the country.

Mexico says over 500,000 guns are trafficked annually from

the U.S. into Mexico, of which more than 68% are made by the

companies it sued.

Mexico said the smuggling has contributed to high rates of

gun-related deaths, declining investment and economic activity

and a need for it to spend more on law enforcement and public

safety. The companies deny wrongdoing.