The US International Trade Commission on Thursday ruled in favor of SK Innovation in its battery patent case against LG Energy Solution, in an unexpected twist in the legal battle.

In its preliminary decision, the ITC said SK had not infringed on any of LGES’ four battery patents in a case that was filed by LGES in September 2019. This is separate from the battery trade theft case, in which the ITC sided with LGES and slapped SKI with a “devastating” 10-year business ban in the US.

The latest ruling comes as SKI makes every effort to overturn the sanctions through a presidential veto.

SKI hailed Thursday’s ruling and reiterated that the company’s battery technologies are original.

“The USITC ruled that three of the four LGES patents are invalid. The ruling vindicates SKI’s independence in battery technology,” the Seoul-based company said in a statement.

The final ruling is slated for Aug. 2.

LGES, for its part, stressed that the case is separate from the theft of trade secrets case, in which the ITC has already delivered its final say.

Responding to Thursday’s ruling, it said that just because some of the claims are ruled invalid, it doesn’t mean a patent is invalid.

“The USITC is saying that certain claims are invalid, not the patents themselves. It’s up to the US Patent and Trademark Office to decide the integrity of those patents, not the USITC,” an LGES official said.

“During the remaining legal procedures, we will do our best to prove the infringement and validity of the patents.”

Although the cases are separate, it remains to be seen how the latest ITC decision might play out in the drawn-out dispute between the two South Korean battery makers. Despite expectations that the two could reach an out-of-court settlement, LGES and SKI have continued their war, with SKI recently threatening to give up its US business if the ban is not reversed.

On Feb. 10, the USITC delivered a final ruling in favor of LGES, confirming that SKI stole battery trade secrets from LGES.

As punishment, SKI was given a 10-year ban in the US on the import, sale and production of electric vehicle batteries. The ban could jeopardize SKI’s $2.6 billion battery plant under construction in Georgia.

President Joe Biden has until April 11 to review the USTIC’s final ruling and decide whether to alter or veto it.

SKI acknowledges that it did steal documents and trade secrets from LGES, but says it didn’t have to use them when manufacturing its EV batteries because its products were actually more advanced than LGES’.

High-ranking SKI officials -- CEO Kim Jun and board chair Kim Jong-hoon -- recently paid visits to government officials in the US and said the company will consider giving up the Georgia plant if it fails to win a veto from the Biden administration.

By Kim Byung-wook (kbw@heraldcorp.com)