Jermaine Jackson retires from the letter against the Estate

Jermaine Jackson -- a major ringleader in the Jackson family rebellion against the Micahel Jackson Estate -- has officially defected from a family letter criticizing the Estate ... but claims he still has "deep reservations" about the Executors, TMZ reported.

Jermaine just posted a long letter on his Twitter account, writing, "I rescind my signature from the letter which was sent to the Estate, and which should never have gone public."

"I still hold deep reservations about many issues involving the Estate, and I will continue to bring scrutiny and a resolute voice wherever we have cause for concern. But the way to address such matters is through the proper channels and via a private dialogue, not public conflict."

He adds, "In this spirit, I offer this statement by way of extending an olive-branch."

Jermaine follows in the footsteps of his brother Tito, who withdrew his signature last week from the siblings' July 17th letter to the Estate, in which they accused the Executors of failing at their job and stressing out Katherine Jackson so badly she suffered a "mini-stroke."

All fake and defamatory allegations and innuendos, already confuted by the Estate. 

As of now, the signatures of Janet, Rebbie, and Randy remain on the letter.