Sprint Nextel sued Clearwire and Dish Network on Monday in a bid to block Dish from taking over Clearwire, Sprint's majority-owned network partner. Dish and Sprint have been in a bidding war over Clearwire, which Sprint also plans to buy, and last week Clearwire's board recommended shareholders accept Dish's offer. But in a complaint filed in the Delaware Court of Chancery on Monday, Sprint said Dish's proposal violates its rights and those of other strategic investors. In its suit, Sprint wants to prevent the deal from being consummated and seeks unspecified damages.