By Katie Marsal

Published: 11:00 AM EST

AT&T said Thursday that fourth-quarter earnings rose over 61 percent, helped largely by its acquisition of BellSouth and the addition of a record 2.7 million wireless customers, many of which are believed to have switched to the provider as a result of Apple's iPhone.

For the three-month period ending December, AT&T said net profit rose 61.8 percent to $3.14 billion, or $0.51 a share, up from $1.94 billion, or $0.50 a share during the same period one year ago.

Sales were up some 91 percent to $30.35 billion from $15.9 billion during the year-ago quarter, boosted largely by the provider's December 2006 acquisition of BellSouth.

During the quarter, AT&T said it added 2.7 million new wireless customers to end at a nation's best 70.1 million mobile subscribers. The surge, thanks largely to Apple's iPhone, helped boost wireless revenues by 16.3 percent to $11.4 billion.

Apple said earlier this week that it sold over 2.3 million iPhones during the same three-month period. The net additions to AT&T's mobile subscriber base are believed to have come largely at the expense of Sprint/Nextel, which warned last week that it had incurred a considerable loss of high-value customers during the December quarter.

AT&T's ability to maintain strength in its wireless business came as some reassurance to investors, after the company said earlier this month that had been forced to disconnect a number of landline subscribers who were finding it difficult to pay more than one telephone bill.

Still, fears of a growing economic downturn continued to weigh on shares of the telecommunications giant, which were trading down $0.93, or 2.5 percent, to $35.76 in early afternoon trading.