Billionaire Carl Icahn's investment company offered to buy the 18 percent of auto parts maker Federal-Mogul Holdings Corp offered to pay $7 per share in cash, sending the company's stock soaring nearly 41 percent to $7.02 in premarket trading. The latest investment from Icahn Enterprises, whose auto business was its second largest by revenue in 2014, comes after a record year of U.S. auto sales and in the same month it closed the acquisition of Pep Boys-Manny Moe & Jack, another U.S. auto parts retailer.