AT&T has reported third-quarter results highlighted by growth in consolidated revenues, strong sales of integrated devices, gains in IP-based and strategic business services, and disciplined execution on cost initiatives. And it activated 5.2 million iPhones in the quarter.

For the quarter ending Sept. 30, AT&T’s consolidated revenues totaled US$31.6 billion, up $847 million, or 2.8%, versus the year-earlier quarter, marking the company’s third consecutive quarter with a year-over-year revenue increase. Versus the second quarter of this year, consolidated revenues were up $773 million, or 2.5%.

Compared with results for the third quarter of 2009, operating expenses were $26.1 billion versus $25.4 billion; operating income was $5.5 billion, up from $5.4 billion; and AT&T’s operating income margin was stable at 17.3%, compared to 17.5 percent.

iPhone activations, spurred by the iPhone 4’s release, were up 62.5% from the previous quarter.