NEW YORK (AP) -- Billionaire investor Carl Icahn plans to make an unsolicited bid for truck maker Oshkosh Corp. (OSK -2.11%) 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.

The activist investor said Thursday that he will make a tender offer worth $32.50 per share in cash, a 21% premium over Oshkosh's latest closing price.

Icahn had sought seats on the board unsuccessfully last year. He said in a press release that management has taken a passive attitude toward the Wisconsin-based company's future and wants it to be more active.

Oshkosh asked its shareholders to take no action on the offer until the board reviews it. The company said its board will advise shareholders of its position within 10 business days.

The company, based in Oshkosh, Wis., makes fire and emergency vehicles, commercial equipment like cement mixers and natural gas tankers, military vehicles like tactical and assault trucks, and access products including scissor lifts, towing equipment, and aerial work platforms. It reported $6.13 billion in revenue in the first nine months of its current fiscal year.

Its shares gained $3.09, or 11.5%, to $29.94 in afternoon trading after rising as high as $31.30 earlier in the day, its highest price since July 2011. The shares are up 36.6% since July 25, the day before the company's fiscal third-quarter report.