Samsung launched its new Galaxy S3 flagship smartphone in Australia back in May, feeling "confident" that the lack of a 4G version would not affect sales of the 3G model. A little over three months later, however, Galaxy S3 fans in Australia have good news coming their way: a 4G model is now set to go on sale.

Australia's second-largest mobile telecommunications provider, Optus, launched its 4G LTE consumer services in Sydney, Newcastle, and Perth on Monday, Sept. 3, with Melbourne to follow on Sept. 15.

The Samsung Galaxy S3 4G is mostly identical to the 3G model, except for the LTE 1800MHz network capability, the letters "LTE" embossed on the back of the handset, and the 4G logo displayed near the coverage bars when in a 4G coverage area. Also, the 4G Galaxy S3 has 2GB of RAM instead of the 1GB of RAM on the regular 3G model. Otherwise, the 4G model is identical in size and weight to the 3G version, and it packs the same Samsung Exynos quad-core processor and the same 2100mAh battery.

In terms of aesthetics, the only real difference between the 3G and 4G Galaxy S3 is in color. While the 3G model comes in "pearl white" and "titanium blue" options, the Galaxy S3 4G will be available in "onyx black" and "titanium gray" variants.

Samsung has also confirmed that the Galaxy S3 4G will ship with the latest version of Google's mobile operating system, Android 4.1 Jelly Bean. The regular version of the smartphone launched with Android 4.0 Ice Cream Sandwich, but it is also expected to receive an over-the-air software update to Jelly Bean in the coming weeks.

The Samsung Galaxy S3 4G will be the first to launch on the brand new Optus 4G network in mid-September, and it will also be available on Telstra's 4G network sometime in October. Optus will sell only the grey model of the Samsung Galaxy S3 4G, while Telstra will carry both the grey and black versions of the smartphone.

Optus is now taking pre-orders for the Galaxy S3 4G on its Web site, and customers who pre-order the device by Sept. 17 should receive it on Sept. 20. It is available either for $7 per month on the Optus $60 plan, or free on the Optus $80 plan, both with a two-year contract. Telstra has not announced pricing or specific availability details yet, but has set up a pre-registration page on its Web site.