As previously reported, Apple’s Q3 earnings reveal that the company is doing pretty well in the Chinese market. Half of the company’s revenue comes from international markets, and China is no doubt high on the list.

CEO Tim Cook says revenue from the country was $5.7 billion in Q3, accounting for a whopping 48% increase year-over-year. Things may soon get even better for Apple in China, despite increased smartphone competition in the region.

Siri does not currently support Mandarin Chinese, which is widely spoken in China and in Hong Kong. A report from Reuters reminded us today that this is about to change this fall.

Update: Wording has been adjusted to reflect that (as a reader pointed out) Mandarin was previously announced as a supported language in iOS 6, which will also come to other versions of the iPhone.

Currently, Siri works in English (United States, United Kingdom and Australia), French (France), German (Germany), and Japanese (Japan). On Apple’s Siri FAQ page, it says that Siri will support addition languages, including Chinese, Korean, Italian and Spanish, in 2012.

Siri can be used in any country in the supported languages, but it’s designed to recognize specific accents and dialects of its supported countries. Clearly, Siri has a great deal of room for growth in that department, and given that Siri has become one of Apple’s main selling points for the iPhone, more language support should have a significant impact on iPhone sales, which haven’t been as great as they have been in previous quarters (though Apple still managed to sell 26 million of them in the quarter).

Of course, Google has added a Siri competitor to its Android operating system, so Apple may also find Siri to become less of a selling point as time goes on.

The iPhone 5 (if that is its real name) is expected to be released in either September or October, depending on which reports you believe. The aforementioned Reuters report is sticking with October, but otherwise, the latest rumor is leaning more towards September.