Apple Inc.’s talks with Hyundai Motor Group have broken down without an agreement for the South Korean auto giant to put together vehicles for the iPhone company.In regulatory filings, Hyundai Motor Co. and Kia Corp. stated that “they are not in talks with Apple over developing an autonomous vehicle.” The two automakers have fielded many requests from other firms to jointly develop autonomous electric vehicles, though no initial steps have been taken.The companies had held talks with Cupertino, Calif. Technology giant regarding a deal for Hyundai subsidiary Kia to build vehicles for Apple in Georgia, The Wall Street Journal reported last week. The prospect of an auto partnership had sent the Korean companies’ stocks surging this year, fueling investor enthusiasm after both Kia and Hyundai had battled years of sinking car sales.Shares dropped 6% for Hyundai Motor following Monday’s regulatory-filing disclosures, while Kia plummeted by more than 13%.