The CEO of Softbank, which is trying to buy a majority ownership in Sprint, says a competing bid from Dish is based on "incomplete and illusory" numbers.

Dish Network Corp. has characterized its $25.5 billion bid for Corp. as superior to Softbank's. In a presentation Tuesday in Tokyo, . CEO Masayoshi Son said the comparison is not "apples to apples" and omits crucial factors.

Softbank agreed in October to buy 70 percent of Sprint for $20.1 billion. That deal is set to close July 1. Dish launched its competing bid for all of Sprint two weeks ago. A committee of Sprint's board is examining it.

view Dish's bid as superior. Son says Softbank's deal is worth 21 percent more than Dish's, all factors considered.