"It is with a very heavy heart and yet great pride that I announce that I've decided to close this chapter of my life and encapsulate the wonderful times that I've shared with Guns N' Roses into fond memories," the letter reads.
The note details how Ashba joined Guns N' Roses and goes on to thank Rose explicitly. He wrote, "I want to take a moment to thank Axl from the bottom of my heart for not only the most incredible experience of my life, but for truly believing in me. You are a true friend and a champion of mine and I am forever grateful. And even as I move on to pursue other endeavors, I will always remain one of your biggest fans."
Duff McKagan on Substance Abuse, Fatherhood and the Possibility of a Guns N' Roses Reunion
Ashba's band Sixx: A.M. includes Mötley Crüe bassist Nikki Sixx and producer James Michael, who fronts the group.
Recently, Ashba made news for proposing to his then-girlfriend Colombian actress Nathalia Henao on a private Las Vegas Metropolitan Police Department helicopter in 2013. That incident ultimately led to the accommodating police captain's retirement and then reinstatement.
Read Ashba's full letter here.