Polypore International Inc., the maker of a key component in electric-car batteries, fell the most in more than three years after a customer announced plans to produce in-house the separators it currently purchases.
The shares decreased 30 percent to $38.08 at the close in New York. That’s the biggest drop since October 2008.
Avinash Kant, an analyst at DA Davidson & Co. in Bend, Oregon, today reduced his rating on Polypore to “neutral” from “buy” on concern that LG Chem Ltd. would begin production this year on the product used to separate chemicals within batteries.
LG Chem’s move may cut into Polypore’s sales to producers of lithium-ion batteries for General Motors Co.’s Chevy Volt and other electric cars, Kant said.
Robert Toth, chief executive officer of Charlotte, North Carolina-based Polypore, remains “confident in the premises used to justify battery-separator expansions associated with accelerating industry demand for electric drive vehicles,” he said today in a statement.