The next major U.S. carrier to reveal its first quarter 2013 report is AT&T. The big blue carrier just shared its Q1 2013 results, and AT&T says that it added a total of 291,000 wireless subscribers in the first quarter. AT&T's postpaid net adds for the quarter finished at 296,000 and its connected device adds ended at 431,000, while its prepaid and reseller divisions lost 184,000 and 252,000 users, respectively.

Looking at smartphones specifically, AT&T says that it managed to gain 1.2 million smartphone subscribers, with smartphones making up 88 percent of all of its postpaid device sales. AT&T reports that, at the end of Q1 2013, 72 percent (48.3 million) of all its postpaid phone subscribers had smartphones. That's up from one year ago when 61 percent (41.2 million) postpaid subscribers had smartphones.

All of those smartphones need data, and AT&T reports that 70 percent of its postpaid smartphone subscriber base (33.5 million customers) is currently on a usage-based data plan. Around 14 percent of AT&T postpaid subscribers (around 10 percent of connections) are specifically on a Mobile Share plan.

Finally, AT&T spilled some of the financial details from its wireless business. The carrier says that it earned total wireless revenues of $16.7 billion for the quarter, which is up 3.4 percent year-over-year. Wireless operating income also saw some growth, expanding 4.1 percent from the year-ago quarter to finish at $4.7 billion.

It sounds like AT&T had itself a pretty decent little quarter. We've watched as smartphone adoption has continued to grow in recent years, and these latest AT&T stats certainly seem to reflect that. As is usually the case with these earnings reports, AT&T is currently holding a conference call to further discuss its Q1 2013 report, and you can bet that I'm listening in. Stay tuned and I'll update you with anything else of interest that AT&T's executives may have to say.

UPDATE: As noted by CNET, AT&T says that it sold a total of 6 million smartphones in Q1 2013. Of that total, 4.8 million were iPhones.

Via AT&T, CNET