A Wall Street research firm is predicting that Apple Inc. (Nasdaq: AAPL) will make more than 40 percent of its $1 billion-plus iPhone revenues in 2008 from carrier payments, all while still having wiggle room to further cut the price of the popular device.

Bernstein Research is the latest firm to try and put a number on how much Apple makes from AT&T Inc. (NYSE: T) on recurring service revenues of the iPhone. AT&T could pay Apple up to $360 in recurring revenues -- or up to $15 a month -- over the course of a typical two year contract, according to a report published Friday by Bernstein analyst A.M. (Toni) Sacconaghi, Jr. (See AT&T's iPhone Deal Bountiful for Apple and iPhone Revenues Flow in Three Streams.)

This kind of generous revenue sharing could allow Apple to further cut the price of the device while still generating more profit from the device than it does from its most expensive iPhone. "If Apple were to reduce the current iPhone's price to $150, we estimate it would still generate gross margins of over 50 percent," writes the research house.

AT&T can afford the high costs of the iPhone because it receives more in average revenue per user (ARPU) from the multimedia-rich iPhone. The firm estimates that AT&T makes $70 to $80 ARPU on iPhone customers, compared to an average of $58 a month for other customers.

Bernstein anticipates, however, that Apple is unlikely to be able to replicate this exact blend of hardware revenue and services fees outside the U.S., "particularly in Asia." (See Report: Apple Picks Euro iPhone Partners.)

Neither Apple nor AT&T have ever revealed any details about who makes what from the iPhone. The research firm reckons that the details are "unlikely to be explicitly disclosed."

— Dan Jones, Site Editor, Unstrung