Citigroup’s research firm say that while the arrangement with AT&T has benefitted Apple, the company is likely to open its smartphone to more US operators within the next two years.
Analyst Richard Gardner cites a number of reasons for this, including the fact Apple is in a strong position and so can have its demands met by carriers.
These extend to generous data plans, a lack of co-branding and an absence of revenue sharing at the App Store.
What is also likely to be a major issue for Apple is the potentially dwindling pool of new iPhone users at AT&T.
It is estimated that rivals Sprint, Verizon and T-Mobile combined could offer a target market of up to 150 million subscribers by 2010 (although only around 20 per cent are likely to become iPhone owners).
While it has been suggested that AT&T is interested in paying to extend exclusivity, the cost to do so might be prohibitive.
As Gardner points it would need to be high since the revenues offered by going with multiple carriers are large.