Following yesterday's announcement that Apple will be launching its iPhone 5 in more than 50 new countries this month, plus reports of improved supply of the device and strong iPhone 4 and 4S sales, analysts have increased their iPhone sales estimates for the December quarter.

Investment bank Canaccord claim that supply of Apple's newest smartphone has "dramatically improved" and that channel checks in November found "very strong sales" of the iPhone 5 internationally, according to CNET.

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This, plus the plans to have the iPhone 5 available across a total of 240 mobile operators in 100 countries, including China, by the end of the year, has led Canaccord to increase its December quarter iPhone sales from 45 million to 47.5 million. Apple sold 27 million iPhones during the last quarter.

China's second-largest wireless carrier China Unicom is reported to have sold more than 100,000 pre-orders of the iPhone 5 within the first day of availability, and China Telecom subsidiary Beijing Telecom is thought to have received more than 5,000 orders when it opened its iPhone 5 sales on Sunday. The iPhone 5 is set to arrive in China on 14 December.

"Bolstered by the iPhone 5, we believe Apple's industry-leading software ecosystem and integrated hardware experience will lead to a strong multi-year product cycle," Canaccord tech analyst Michael Walkley said.

Walkley thinks that December's solid sales performance will lead to a gross margin of around 38.7 per cent, up from Apple's 36 per cent guidance.

Forbes' Chuck Jones notes that Wall Street analysts have estimated that Apple could sell somewhere between 43 to 53 million iPhones in the December quarter, but places his prediction on the 50 million mark.

Sales of the iPhone 4 and 4S are believed to have remained strong through November, despite the iPhone 5's launch, and many stores in the US had reportedly sold out of the iPhone 4 following Black Friday sales.

AllThingsD reports that Consumer Intelligence Research Partners (CIRP) has found that the iPhone 5 accounted for 68 per cent of the total iPhone sales during the month following its launch. That's much less than the 90 per cent of iPhone sales scooped up by the iPhone 4S during its first month of availability.

This indicates that Apple is selling an increasing amount of lower priced iPhones to consumers, which will gradually lead to a compression of the iPhone's average selling price (ASP), and in turn have an effect of Apple's profit margins.

"ASP compression naturally leads to margin compression, which is a big fear of Apple shareholders as their markets become more competitive," CIRP co-founder Michael Levin said. "They had record margins in recent quarters, healthy and even growing at times, which is unheard of for a company of Apple's size and market share in smartphones and tablets. These margins may have started to moderate somewhat with the launch of the iPhone 5."

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