High Tech Computer (HTC) stated selling self-branded Windows Mobile smartphones for the first time last year. The veteran original design manufacturer has just announced it would make free upgrades to Windows Mobile 6, Microsoft’s newest wireless operating system, available for all of these devices, in addition to some of its operator-branded models, starting in June.

HTC smartphones currently running Windows Mobile 5 due for Windows Mobile 6 upgrades include the Advantage, the TyTN, S620, P4350 and P3300. The company says it chose these devices for platform updates because they would greatly benefit from Windows Mobile 6 enhanced messaging capabilities.

It hasn't ruled out making it available for other devices as well, but availalbity will depend on demand.

The recently announced HTC S710 is set to be one of the first devices to actually ship running on Windows Mobile 6.