The wireless network is suing to prevent Dish Network (DISH) from buying broadband wireless network operator Clearwire (CLWR). Sprint Nextel (S), Clearwire's largest shareholder, said the deal violates shareholder rights. Sprint claims Dish needs approval of 75% of Clearwire's shares. Dish offered to pay $4.40 per share for Clearwire vs. the $3.40 Sprint offered. Sprint shares rose 1.4%. Dish rose 0.7%. Clearwire fell 1.5% to 4.56.