With both AT&T Inc and Verizon Wireless, the two top US mobile operators, keen to tie-up with apple for distribution arrangements for its popular iPhone, speculation about who will finally make it is rife in the industry. According to industry sources whether one or both operators finally sign up, Apple will be the final winner.

Apple and AT&T already have a deal going, which is believed to run till 2010 under which AT&T will carry the iPhone on its Global Service Mobile (GSM) network. According to analysts, Apple is believed to earn a profit margin of more than 50 per cent on the iPhone.

But they add that Lowell McAdam, the head of Verizon Wireless, recently had discussions with Apple's chief executive, Steve Jobs, and other senior Apple executives about carrying an iPhone on its network.

They say it makes as much sense for Verizon to tie-up with Apple, as for AT&T to ensure that a Verizon-Apple tie-up does not materialise. In such a scenario, they aver Apple is the clear winner.

With Verizon as a carrier Apple could more than double its current addressable market; AT&T has about 78.2 million wireless customers, while Verizon has 86.6 million according to the companies' recent quarterly reports.

But AT&T, with 1.6 million iPhone activations in the first quarter of this year is not expected to yield its iPhone exclusivity. It sells iPhone for as little as $199 after paying a huge subsidy to Apple to boost sales.

The iPhone has also helped the company substantially increase its subscriber base in a slowing market in which most people already own mobiles.

Apple has said it is not interested in offering a phone for Verizon's CDMA network, which has limited presence across countries as against the rival GSM standard AT&T users.

Verizon Wireless however plans to start building a new network based on LTE, an emerging high-speed wireless technology which will be adopted by other operators around the world.

Meanwhile, Apple is expected to release a new iPhone later this year. This will come with some sort of a small touch-screen computer.

Analysts however, believe that there is one big question over a potential Verizon Wireless tie-up – whether Verizon would be willing to give the same level of control to a phone maker that AT&T had given to Apple.

For example, iPhone software applications are exclusively sold through Apple's App Store.

Verizon also has a mobile search agreement with Apple's arch-rival Microsoft. The two are also jointly developing a touch-screen cellphone to rival iPhone, according to a media report.

According to the report the phone would be made by a third party and will be launched early next year. The report said both Verizon and Microsoft declined to comment.

The report said Apple declined to comment on rumours and Nataie Kerris, spokeswoman for Apple said, while affirming the company' support to AT&T that AT&T had done a very good job with iPhone putting the full force and weight of the company behind it. She added that Apple was happy with the relationship and had no plans to change it, the report said.