On GACKT's official site, there is an announcement that he will be releasing his 39th single (title unknown yet) on July 13th.

Though no information about the new single has been revealed, there will be two different versions for the single; limited edition which will come out with a DVD, and regular edition. �It will be about a year since he last released his single "EVER" back on July 28th, 2010.

We will report with more details when it's revealed, so stay tuned!

Source: GACKT Official Site

Thanks to tika for the tip!