Billionaire investor Carl Icahn plans to make an unsolicited bid for truck maker Oshkosh Corp. that values the company at almost $3 billion. Icahn says he also plans to nominate his own slate of directors in a bid for control of the company. He said Thursday that he will make a tender offer worth $32.50 per share in cash, a 21 percent premium over Oshkosh’s latest closing price. Icahn had sought seats on the board unsuccessfully last year. He said he owns about a 10 percent stake in the company. Oshkosh asked its shareholders to take no action on the offer until the board reviews it. The company makes fire and emergency vehicles as well as other types of vehicles.