AT&T (http://www.att.com) has reported strong first-quarter results. The company activated 2.7 million iPhones during the period — that’s 1.1 million more than it did a year ago.

For the quarter that ended March 31, AT&T’s consolidated revenues totaled US$30.6 billion, up $78 million, or 0.3% versus the year-earlier quarter; operating expenses were $24.6 billion versus $24.8 billion; operating income was $6.0 billion, up from $5.7 billion in the first quarter of 2009; and AT&T’s operating income margin was 19.6%, up from 18.8 percent in the year-earlier quarter.

First-quarter 2010 net income attributable to AT&T totaled $2.5 billion, or $0.42 per diluted share, reflecting a previously disclosed noncash charge of $995 million, or $0.17 per diluted share, related to recently enacted changes in the tax treatment for the Medicare Part D subsidy. Excluding this charge, first-quarter earnings would have been $3.5 billion, or $0.59 per diluted share. These results compare with net income of $3.1 billion, or $0.53 per diluted share, in the year-earlier first quarter.