Already surpassing the 20 million milestone in the past few days, Samsung believes it will see more than 10 million additional sales of its flagship Galaxy S III smartphone by the end of the year, solidifying its position as the company’s most successful smartphone ever.

Speaking with Korean media, Samsung’s IT and Mobile chief Shin Jong-kyun said: “The Galaxy S3 is expected to sell more than 30 million units within this year.”

Shin also commented on the launch of the new Galaxy Note 2 (a device unveiled last month at IFA 2012 in Berlin), believing the smartphone-cum-tablet will double the sales of its predecessor — which has sold more than 10 million units.

The Galaxy Note 2 is yet to go on sale and is scheduled for an October launch. Shin also denied rumors suggesting the Korean electronics giant would push the release date forward to better compete with Apple’s new iPhone (launching today).

In July, Samsung announced that the Galaxy S III had hit 10 million sales, less than two months after its launch. This equated to roughly 190,000 sales a day of the Android-powered smartphone. However, between July and September, sales of the Galaxy S III increased to more than 215,000 sales a day, reaching the 20 million mark last week.

If Samsung can continue to keep up its sales rate, it can expect to reach the 30 million mark by October 28, 2012. However, with sales of Apple’s new iPhone believed to commence on September 21, Samsung is expected to lose some of its competitive edge. New Apple products have a history of getting off to fast starts — the iPhone 4S saw more than 4 million sales in its first weekend.

Shin’s comments would suggest that the company has taken that into consideration, effectively giving it more than three months to reach that total.