Family Dollar Stores Inc. (NYSE:

)k shares jumped nearly 3 percent after-hours Thursday on news that activist investor Carl Icahn wants the company "put of for sale immediately." Icahn acquired a 9.4 percent stake in the company Monday and the text of his letter to management demanding the sale was filed with the Securities and Exchange Commission Thursday after the market closed. Icahn said without company cooperation he will wage a proxy fight, although he called that a "last resort" and prefers to work cooperatively with management. Icahn seeks to add three members to the board and have it pursue a sale. Strategic and financial buyers "could recognize massive synergies from an acquisition," Icahn said in the letter mentioning a dinner he had with management Wednesday evening. In after-hours trading, Family Dollar was changing hands recently at $69.91, up 2.6 percent.