(Reuters) - Clearwire Corp said on Wednesday that it would draw on $80 million in financing from Sprint Nextel Corp , which is seeking to buy it, but vowed to continue talks with rival bidder Dish Network Corp . Shares of Clearwire fell 1.5 percent to $3.15 after the decision, which could end Dish Chairman Charlie Ergen's effort to buy the wireless service provider. But the stock was still above Sprint's offer price of $2.97 per share, showing that investors still held out hope for a higher valuation. ...