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* SoftBank, Dish seek to buy Sprint
* Sprint, Dish seek control of Clearwire
* Lawsuit filed in Delaware Chancery Court
By Jonathan Stempel and Sruthi Ramakrishnan
June 17 (Reuters) - Sprint Nextel Corp on Monday saidit has sued Dish Network Corp to block its tender offerfor Clearwire Corp, on the eve of a key deadline in atakeover battle that also includes Japanese mobile carrierSoftBank Corp.
The lawsuit filed on Monday in Delaware Chancery Courtaccuses Dish of trying to "fool" and "coerce" Clearwireshareholders into tendering their shares, and rejecting Sprint'scompeting effort to buy the 49.8 percent it did not already ownof the wireless broadband provider.
It came one day before a deadline for Dish to sweeten itsearlier $25.5 billion bid to buy Sprint, which has endorsed acompeting bid by SoftBank.
Sprint said Dish's offer would leave non-tenderingshareholders owning stock in a company "handicapped by unlawfulcorporate governance restrictions, onerous debt provisions, andpotentially ... subject to massive money damages claims payableto Dish - an entity which has everything to gain from a failureof Clearwire."
The lawsuit also names Clearwire as a defendant.
Last week, Clearwire's board urged shareholders to acceptthe Dish tender offer, which values Clearwire at $4.40 pershare. Sprint has offered $3.40 per share forthe Clearwire stock it does not own.
Dish spokesman Bob Toevs said: "We are reviewing thecomplaint and considering our options."
Clearwire spokeswoman Susan Johnston said that company doesnot discuss pending litigation.
JUNE 18 DEADLINE
The lawsuit adds a new complexity to a takeover battle inwhich SoftBank and Dish are bidding for Sprint, while Dish andSprint are bidding for Clearwire.
Last week, SoftBank raised its offer for Sprint to $21.6billion from $20.1 billion, which would give it a 78 percentstake in the Overland Park, Kansas-based company.
The new offer includes $16.6 billion of cash, and would bethe largest overseas acquisition by a Japanese company.
Sprint then gave Dish, a satellite TV provider controlled bybillionaire Charlie Ergen, until June 18 to sweeten the $25.5billion bid, which it said is not "actionable," and make itsbest and final offer.
Dish is based in Englewood, Colorado, and Clearwire inBellevue, Washington.
WIRELESS MOVES
Known for pursuing fierce takeover battles, Ergen isinterested in Clearwire to expand into wireless amid a maturingof Dish's traditional pay-TV business.
Sprint, meanwhile, hopes to use Clearwire to help it bettercompete in mobile communications with larger rivals AT&T Inc and Verizon Wireless .
SoftBank had approved the Sprint bid for Clearwire, but saidit would be content even if shareholders rejected that bidbecause Sprint would still control a majority of the company.
The Japanese company is controlled by billionaire founderMasayoshi Son, who is known as a risk-taker despite hiscountry's normally cautious corporate culture.
Shareholders of Sprint are scheduled to vote on the $21.6billion SoftBank offer on June 25.
Paulson & Co, the hedge fund firm run by billionaire JohnPaulson and Sprint's second-largest shareholder, has said itwould vote for the SoftBank transaction.
The lawsuit was announced after U.S. markets closed. InMonday trading, Sprint shares closed down 10 cents at $7.22,while Clearwire shares were unchanged at $4.63.
The case is Sprint Nextel Corp et al v. Dish Network Corp etal, Delaware Chancery Court.
