Sales of Apple’s new iPhone 5 smartphone reached two million units in China just three days after launch, the company has announced.

Being offered through China Unicom and China Telecom along with Apple’s retail store, the firm has received 300,000 pre-orders for the new smartphone with China Unicom. However as pointed out last week Apple’s failure to offer the iPhone 5 through China’s biggest mobile carrier could hurt sales.

The highly-expected release in China, which is the iPhone maker’s second-biggest market, has, however, not alleviated fears of the heavy competition in smartphones that are causing the share price of Apple to plummet. From a high of $700 per share in September this year, Apple’s share price has steadily fallen since. It now sits at just over $500.

Investors are worried that Apple’s dominance in the smartphone market is being challenged by the likes of Samsung and Google’s Android operating system. The company is also under pressure in the mini tablet arena, with Google’s Nexus range and Amazon’s Kindle Fire both doing well. That pressure saw Apple hit back with the iPad mini.

Apple CEO Tim Cook said customer response to iPhone 5 in China has been incredible, as it set a new record with the best first weekend sales ever in the Asian country.

"China is a very important market for us and customers there cannot wait to get their hands on Apple products," Cook said.

Powered by iOS 6, the new iPhone 5 is claimed to be the thinnest and lightest iPhone ever, and its new features include a new 4in Retina display, an A6 chip for fast performance, wireless technology, shared photo streams, all-new Maps app, Passbook organisation and Siri features and languages.

Apple is also planning to launch iPhone 5 in more than 100 countries by the end of December 2012, which will make it the fastest iPhone rollout ever.