Wireless Broadband provider, Clearwire (CLWR), which previously agreed to be bought out by Sprint Nextel (S), received an unsolicited offer from DISH Network (DISH) on Tuesday.

DISH offered to pay $3.30 a share to acquire as much as all of Clearwire.  However, in December, Clearwire entered into a definitive agreement with Sprint to acquire the roughly 50% stake in Clearwire Sprint doesn’t already own, for $2.97 per share.

Prior to that agreement, DISH also provided Clearwire with preliminary interest in acquiring certain spectrum assets priced at nearly the same $3.30 per share offer the company made Tuesday. At that time, Clearwire determined the Sprint transaction to be more favorable for the company’s shareholders, and proceeded with the agreement.

Clearwire said the proposal from DISH on Tuesday is only a preliminary indication of the company’s interest and its consideration is significantly limited by its current contractual agreements with Sprint. The company said it has not made any decision to change its recommendation of moving forward with the Sprint transaction.

Sprint called the offer from DISH “illusory” and “inferior” to its agreement with Clearwire.  
Shares of Clearwire surged close to 10% to $3.20 in extended trading Tuesday as the potential bidding war emerged.