Apple is on track to sell a record number of iPhone handsets in the December quarter thanks to the launch of its latest smartphone, the iPhone 4S. UBS analyst Maynard Um was one of a number of analysts in recent weeks to raise his estimates on iPhone sales for the fourth calendar quarter, and he now believes Apple will offload as many as 30 million smartphones this quarter. Apple now sells three iPhone models: the new iPhone 4S, which broke Apple’s previous record when it sold more than 4 million handsets during the phone’s debut weekend alone, the iPhone 4 and the iPhone 3GS. In the U.S., recent checks indicate that the iPhone 4S and iPhone 4 are still among the best-selling smartphones in the country, and Apple’s iPhone 3GS — which is now free on contract at AT&T — is reportedly still in high demand as well. Um is sticking with his previous iPad sales estimates for the fourth quarter. The analyst believes Apple will move 12 million iPads between October and December, though he did note that strong holiday sales could push that figure up to 13 million units.