Apple could sell as many as 30 million iPhones in the final three months of 2011.

Analyst Maynard Um at investment bank UBS revised his previous estimate of 28 million handset sales for Apple in Q4 2011 up by two million this week, reports Apple Insider.

Um's new estimate comes after US network provider AT&T predicted a bumper quarter for handset sales and demand for the new iPhone 4S, which shows little sign of abating in many markets. 

The 30 million forecast puts UBS' estimate slightly ahead of those offered by Mark Moskowitz of JP Morgan, who last week raised his prediction from 25.3 million to 28 million.

Shaw Wu of Sterne Agee also thinks Apple will sell 28 million iPhones in Q4 2011, he said earlier this week. Wu also raised his estimates for sales of Macs for the quarter from 5 million to 5.2 million, though he reduced his predicted figure from iPad sales from 15 million to 13.5 million.

Um, meanwhile, stuck to his original estimate of 12 million iPad sales in the final quarter of the year. Moskowitz, though, thinks Apple will sell 13 million iPads in the quarter and 5.4 million Macs.