Apple (AAPL.NASDAQ) released the iPhone 5 in mainland China on Friday, sales of which should help the company regain recently lost market share in the nation with the world’s strongest smartphone demand, Reuters reported. More than 300,000 iPhones have been ordered in advance on one carrier alone, a sign that the new product launch will lead to a rise in sales. China is Apple’s second-biggest and most rapidly expanding market. But the company’s rate of growth in China is slower than other brands, leading its position in the smartphone market to fall from fourth to sixth in the third quarter, according to research firm IDC. Apple’s failure to agree to a deal with China Mobile, the mainland’s largest mobile phone carrier, to offer the iPhone means it is unable to tap a significant number of users.