The long rumored HTC One A9 smartphone, codenamed "Aero," will reportedly be shipped running the new Android 6.0 Marshmallow OS by default. The OS is also said to be layered with HTC's own Sense 7 user interface.

On Monday, an Android ROM developer going by the Twitter handle "@LlabTooFeR" posted a tweet claiming that the handset will be powered by Android 6.0 out of the box. LlabTooFeR, who is a frequent source of HTC-related leaks, furthered suggested that the model will be unveiled around October or November.

This leak adds to the growing number of speculations surrounding the Taiwan-based device maker's unannounced handset. Last week, the HTC One A9 was also reportedly benchmarked by GeekBench which incidentally revealed a handful of details about its specifications.

Back then, the Aero model was said to feature a deca-core Helio X20 processor clocked at 1.96 GHz and partnered with a large 4 GB worth of RAM. While the new info suggests that it will run the upcoming Android build, the GeekBench listing indicated that it will run the current Android 5.1.1 version. Other high-end features include a 5.2-inch QHD screen, 13-megapixel camera, 3,500mAh battery, fingerprint scanner, and a 7mm-thin body.

All of those specs indicate that the One A9 might be a premium flagship model. However, renowned leakster Evan Blass' ("@evLeaks" on Twitter) latest revelation suggests that the model will just be a mid-range device.

He revealed via a Twitter post that the HTC One A9 will be equipped with a Qualcomm Snapdragon 617 chipset, 2GB RAM, and a 5-inch AMOLED screen with FHD resolution. It will have a 13MP main camera coupled with a 4MP Ultra Pixel front shooter, like the one found on the HTC One M8. Memory expansion is also apparently supported via microSD and a smaller 2,150mAh battery is fitted.

Blass agrees to earlier speculations that the smartphone will have a fingerprint sensor and a 7mm-thin metal body. He also added that it will come in 6 different colors and will be launched on November.

While@LlabTooFeR and @evLeaks both hinted that the HTC Aero device will be launched within the October-November timeframe, there is a report coming out of Taiwan that the company will hold a launch event on September 29.

It is interesting to note that that Google is also holding an event on the same date. It is widely believed that it is the venue where the search giant will unveil its new co-branded devices that run the latest Android 6.0 Marshmallow OS--the LG Nexus 5X and the Huawei Nexus 6. Even if HTC decides to launch its Aero model on September or even November, the One A9 will still be one of the first non-Nexus handsets to arrive running the new Android build on board.