iPhone 4 remains sold out at half of Apple's US retail stores

Analyst Gene Munster polled 30 retail stores this week, and found that 16 of them had some stock. Most stores he checked with indicated they are receiving daily iPhone 4 shipments to meet up with supply.

Despite limited supplies, the situation is improving. Before July 10, there was no in-store availability, with 0 of 20 stores in stock. On July 26, Munster polled 5 stores and found 3 had the iPhone 4 available.

The continued limited supply, he said, is evidence that demand for the iPhone 4 remains strong despite the "antennagate" controversy, which erupted when users realized that covering the bottom left corner of the handset could reduce reception. Supply constraints are not a sign of a production slowdown, Munster said.

"We had expected near full in store availability in the U.S. by now, given it has been several weeks since the iPhone 4 U.S. launch (June 24)," he wrote. "Longer than expected supply shortages are not new to the iPhone. As a point of reference, in last year's September quarter conference call, the company indicated that iPhone supply was constrained in most countries through late Sept. or early Oct. due to better than expected demand of iPhone 3GS."

The iPhone 4 sold a record 1.7 million units in its first three days, making it the fastest selling Apple product in history. Munster believes that in the September quarter, Apple will sell 11 million units worldwide.

Piper Jaffray has maintained its overweight rating for AAPL stock with a price target of $371.