Update: Sprint provided the following statement to The Wall Street Journal:

Sprint (NYSE: S) today confirmed that it is currently engaged in discussions with Softbank regarding a potential substantial investment by Softbank in Sprint. Although there can be no assurances that these discussions will result in any transaction or on what terms any transaction may occur, such a transaction could involve a change of control of Sprint. Sprint does not intend to comment further unless and until an agreement is reached.

According to a report from Nikkei (via Bloomberg), Japan’s Softbank, the third-largest mobile carrier in the country, is currently seeking to acquire two-thirds of U.S.-based Sprint Nextel Corp. The price is rumored at roughly $19 billion USD and would make AT&T the last fully U.S.-based carrier:

Softbank Corp. (9984), Japan’s third- largest mobile-phone company, is in talks to buy control ofSprint Nextel Corp. (S), according to two people familiar with the matter…The deal would give Softbank a base for entering the U.S. market with a compatible carrier that uses similar equipment made by Sweden’s Ericsson AB, the Nikkei reported.