The company said that 98% of the votes cast today voted in favor of the transaction. Those votes accounted for around 80% of Sprint's outstanding common stock as of April 18.
"The transaction with SoftBank should enhance Sprint's long-term value and competitive position by creating a company with greater financial flexibility," said Sprint CEO Dan Hesse.
SoftBank had been battling satellite-TV provider DISH Network (NASDAQ: DISH ) since April 15 for the right to buy Sprint. It was only last week that SoftBank seemed destined to come out on top when it sweetened its proposal with an additional $4.5 billion in cash for shareholders.
SoftBank's original agreement with Sprint was for $20.1 billion for 70% of the No. 3 U.S. wireless provider. The voted-upon agreement raised that price to $21.6 billion for a 78% slice of Sprint, and it will put up to $16.64 billion into the pockets of Sprint stockholders.
The Sprint-SoftBank transaction is still subject to approval by the Federal Communications Commission. The companies anticipate the deal to be completed in early July.
Editor's note: A previous version of this article contained incorrect information about Softbank's offer. It has been corrected. The Fool regrets the error.