Taiwan-based mobile phone maker HTC is gearing up for the release of a new mobile phone on September 15, at least this is what the invites it sent out for an event held in London on that very day suggest.

It seems that it might not be too long before HTC unveils to the world a new mobile phone that runs under Google's Android operating system, according to the teaser image that can be seen on that September 15-event invitations the smartphone designer has been sending out to UK-based media.

Unfortunately, there are no specific details on what the said device would be all about, the most of the rumors around the Internet suggest that we're to expect a new Android-based phone being launched, most probably the sequel to the first such handset from HTC, the popular G1.

According to a recent article on Gizmodo, the device could be the one and the same G1 Blaze/HTC Vision device that would put together Android and HSPA+ connectivity on T-Mobile USA's airwaves, though it is rather strange that HTC chose to announce it officially in the UK, and not stateside.

Chances are that this is actually another Android-based phone from HTC, such as the previously leaked HTC Desire HD, which was spotted not too long ago in Vodafone's systems, and which was rumored to be the European flavor of HTC EVO 4G, though with no WiMAX on board, namely the HTC Ace.

Based on the latest leaks on HTC's roadmap, we might easily conclude that this is another device than the HTC Desire HD, or the G1 Blaze/HTC Vision, the official confirmation on the device should arrive only one month from now, at the said press event HTC is readying in London.

As Gizmodo points out, there are little chances that the device in question would be a Windows Phone 7 handset, since Microsoft already announced that the first such phones would ship in October, but we should consider this possibility too.

The bets seem to be on Desire HD, since the “button-shaped image” that can be seen in smoke on the invite resembles the lens of this device, as EuroDroid notes.