The HTC One Max is already being assessed by carriers and will go on sale in Australia shortly.
The phablet join the HTC One with its 4.7-inch FullHD display and the HTC One Mini, which has a 4.2-inch 720p HD display.
HTC has not said when the device will go on sale in Australia.
Its big-screen counterpart would come to the U.S., but Sprint and Verizon will offer it in time for holiday sales, HTC said.
Like the HTC One, the One Max features a quad-core 1.7GHz CPU what is new is a built-in fingerprint scanner, which is on the back and lets users lock or unlock the screen. Users can also quickly launch up to three pre-selected applications by assigning an individual finger to each app.
The One max also adds the company's upgraded Sense 5.5 user interface and dual-capture capability, which lets users simultaneously shoot pictures or videos from the front and rear cameras simultaneously to deliver picture-in-picture capability.
HTC has not provided many details but said the new phone will come with 16GB or 32GB onboard memory depending on the carrier, a MicroSD card slot, 50GB of additional free Google Drive online storage, a 3,300 mAh embedded battery and an optional HTC Power Flip Case, which incorporates a 1,150 mAh battery for additional battery life.
Like the two other models in the One series, the One Max will feature HTC BlinkFeed, HTC Zoe and HTC BoomSound. BlinkFeed constantly feeds social-network updates, HTC-curated information services incorporating content from 1,400 sources such as ESPN and Reuters, and other content to home screen tiles that extend below the screen. Key applications such as calendar and music player also appear on home-screen tiles.
HTC Zoe lets users simultaneously capture a picture and three-second HD video and automatically stitch together multiple Zoe photos and videos into a Highlights Video with background music, transitions, and effects.
BoomSound consists of front-facing stereo speakers with a dedicated amplifier.
All three phones also feature UltraPixel front camera, said to use large pixels to capture 300 percent more light than standard camera sensors.
With the Sense 5.5 upgrade, BlinkFeed is said to offer a more personalized experience, enabling users to create customizable topic categories. It also integrates with new content providers such as Instagram and Google+.