Achary was found guilty of five counts of indecency without consent and five counts of breach of the Leadership Code Act.
He pleaded not guilty in the trial, but the Supreme Court found him guilty of all charges.
Achary resigned ahead of a decision from the Fund's board.
He confirmed his resignation to the Daily Post.
"I resigned to protect the name of the institution. The institution is more important to me than myself.
"I have worked very hard to build the institution since I came to Vanuatu," he told the newspaper.