In its last full quarter of being the sole carrier of the popular Apple iPhone, AT&T's profit fell 60 percent and the company expressed concerns about the future.

This is going to create some volatility in the first part of the year, AT&T chairman and CEO Randall Stephenson said during the company's earnings call. It may be rocky, volatile, hard to predict in the beginning of the year.

Even as he admitted that losing exclusive rights to the iPhone would be a problem, Stephenson said he is confident AT&T would stabilize and grow its subscriber base. He said in the fourth quarter of last year it became clear the iPhone would be launched on another network. Yet despite this being common knowledge, AT&T had its second best integrated sales quarter ever. People knew the iPhone would be on another network and went with AT&T anyway.

Stephenson said the company also had a great quarter in regards to iPhone sales. The company's four million iPhones activated was up from 3.1 million a year ago. However, it was down from more than five million in the third quarter of 2010.

The number of added subscribers in the fourth quarter also fell to 400,000 from 1.3 million in the year ago quarter. The number was also below analyst expectations.

To cure the lack of iPhone exclusivity blues, Stephenson said the company is going to aggressively promote some of its Android phones as well as phones from other operating systems. We're going to be a heavy participant in the Android market this year, so you'll see a significant shift in mix and then you add Windows 7 and [Research in motion]'s product. We think we'll have a nice mix shift, he said.

AT&T has several new Android phones including the Motorola Atrix 4G, HTC Inspire 4G and Samsung Infuse 4G. For Windows phones, it has the LG Quantum, Samsung Focus and HTC Surround. It also has several R.I.M. blackberries.

The company's revenue was $31.4 billion, up $653 million, or 2.1 percent, from the year ago quarter. However, its profit was $1.09 billion, or 18 cents a share, down from $2.73 billion, or 46 cents per share in the prior year. AT&T attributed this to a pension accounting change and severance costs, and said without those one-time charges, EPS was actually $0.55.

One positive from AT&T's earnings call was its total subscribers went over 95 million. By passing 95 million, the company has surpassed Verizon in the total amount of subscribers in the U.S. Verizon has approximately 94 million subscribers.

The fact AT&T is losing its iPhone exclusivity was not lost on analysts. Craig Moffett from Sanford Bernstein wrote in a note that the disappointing fourth quarter of 2010 represented the twilight of monogamy for AT&T.