NEW YORK -- Dish Network (DISH) - Get Report is proposing to merge with Sprint Nextel (S) - Get Report in a $25.5 billion deal.

Sprint, the No. 3 U.S. wireless carrier, had agreed to be acquired by

Softbank Corp.

of Japan.

Dish is offering to pay $7 a share for Sprint -- $4.76 in cash and about $2.24 in Dish stock.

Sprint shares were up more than 10% in premarket trading on Monday.