The news comes after shareholders in Spirit Nextel, the third biggest wireless operator in the US, backed the company’s revised bid for a 78 percent stake in the business.
In taking control of this stake SoftBank will pay $21.6 billion, a figure that makes it the largest overseas acquisition by a Japanese firm in history.
"The transaction with SoftBank should enhance Sprint's long-term value and competitive position by creating a company with greater financial flexibility," Dan Hesse, chief executive of Sprint said in a statement.
According to the deal, Sprint shareholders will have the option to receive either $7.65 in cash or one New Sprint common stock for each share of Sprint common stock they hold. The total cash consideration available to Sprint stockholders is $16.6 billion.
US satellite TV operator Dish Network had also tabled a rival bid of $25.5 billion for Sprint. However, its offer, while higher than that of SoftBank, would have increased Sprint's debt burden and was seen as more risky.
