Dr Slater, who served as NICTA's chief executive officer and president, said he would not be resigning if he was "not supremely confident that a strong foundation has been laid for NICTA's continued success".
A member of the NICTA board, Dr David Skellern, has been appointed to the position of deputy chief executive officer until 31 May, from which he will assume the position of interim chief executive officer. The search for a new chief executive officer is to start straight away.
Dr Slater said the timing for starting NICTA "could not have been more fortuitous".
"When the world economy entered a slump in information and communications technologies, Australia had the foresight to invest in the future.
"At a time when leading researchers around the world were questioning the opportunities in front of them, NICTA had the opportunity and the funding to lure many of the world's leading researchers in information and communications technology to Australia".
