Sprint estimated to sell 6 million more US iPhones for Apple in 2012

According to a note by analyst Gene Munster of Piper Jaffray, the addition of Sprint to Apple's US carrier mix, as reported to be in the cards by the Wall Street Journal, would increase Apple's estimated 2012 phone sales from 111 million to 117 million.

The estimate is modeled after Verizons' sales of 4.6 million iPhone 4 units in the first half of the year. The analyst expects Verizon to sell 12 million iPhones in its first year of sales, roughly 11 percent of its phone mix.

If Sprint sells a similar percentage of iPhones, it would amount to 6 million new sales for Apple next year across its 52 million subscribers.

In the most recent quarter, AT&T sold about 3.6 million iPhones and Verizon sold 2.3 million, together accounting for about 30 percent of Apple's global smartphone sales.