U.S. mobile carrier T-Mobile has announced it will cut up to $50 off device-only pricing in an across-the-line sale, according to a leaked internal sales memo obtained by TmoNews.

The company's full-price, off-contract 16GB iPhone 5S is now $600. The 32GB model is selling for $700, and the 64GB version is going for $800.

T-Mobile offered similar treatment to the 16GB iPhone 5C, which is now going for $500 off-contract with a $50 discount from the previous price. The 32GB iPhone 5C is selling for $600 with a $48 price cut.

The carrier has not confirmed if the price cut is temporary or permanent.

T-Mobile becomes the latest company to drop iPhone pricing ahead of Apple's expected iPhone 6 release sometime this fall.

Earlier this month, Walmart announced its own savings plan with a 90-day sale that drops 16GB iPhone 5C models down to 97 cents and 16GB iPhone 5S devices down to $79, with a two-year contract.

Earlier this week Verizon also initiated aggressive discounts on both the iPhone 5S and iPhone 5C devices in an attempt to run through inventory before Apple introduces its next phone.

The largest carrier in the nation is burning through the 32GB iPhone 5C device without restocking, which could mean Apple might discontinue the mid-tier version when the next release cycle hits.

Apple has scheduled a special media event for Sept. 9, and most analysts expect the company to unveil its new iPhone with both 4.7-inch and 5.5-inch screens.

Both devices would be much bigger than the 4-inch screen found on the iPhone 5S and 5C.

If the company follows its normal launch schedule, Apple fans can expect the iPhone 6 to be released on Sept. 19.

Apple has not confirmed any news regarding its next iPhone yet. Some analysts expect sales for the new device to reach 10 million during the device's launch weekend, and 15 million by the end of the September quarter. 

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