AT&T said on Sunday it would buy T-Mobile USA from Deutsche Telekom for $39 billion, creating the largest wireless company in the United States from what were the nation’s second and fourth providers.

The combined entity would be about a third larger than the current No. 1, Verizon Wireless, and boast more than twice the subscribers as Sprint Nextel, the Wall Street Journal reported.

AT&T put up $25 billion and the rest in stock, according to the companies’ press release, which stated that the transaction would take about 12 months to close. Shares in the company closed at $26.21 on Friday.

If it passes regulatory and shareholder approval, the tie-up will consolidate the only two remaining GSM providers in the United States — AT&T acquired Cingular in 2007 after a complicated string of mergers among the former Baby Bells — and would likely improve available spectrum for both.