Crediting the rise in the sales of Apple's iPhone as well a range of other smartphones available in the market, AT&T has posted a striking 26% rise in its second-quarter incomes amounting to US$4 billion.

The wireless network of AT&T posted a 1.6 million increment in the customer base in the period, other than an increase in smartphone and e-reader customers.

The net revenues observed in the quarter equaled $30.8 billion, rising by more than 0.6% in the preceding year.

The revenues coming in from wireless network amounted to $12 billion in the second quarter of 2009, rising to $13.2 billion in the second quarter of the current year.

As many as 3.2 million iPhone users have been added to the AT&T network, over the last one year, accounting to more than 27% of the activations in the last one year.

AT&T is in exclusive partnership with Apple for usage in iPhone across the U.S. Apple had launched iPhone 4 on June 24.

"We again delivered a very strong set of financial results. We've got terrific momentum in wireless", said Rick Lindner, AT&T's Senior Executive Vice President and CFO.

The income for the second quarter, when calculated on per share basis, accounts $0.68.