The Director General of FÁS, Rody Molloy, has resigned.
The announcement was made shortly before 11pm by Tánaiste and Minister for Enterprise Mary Coughlan.
In her statement she thanked Mr Molloy for his many years of public service both in the Department of Enterprise, Trade & Employment and for the past eight years as Director General of FÁS.
Mr Molloy's resignation follows a week of controversy and allegations of excessive expenses incurred by executives of FÁS.
In a statement, State training agency FÁS said it would continue to cooperate with investigations by the Public Accounts Committee and the Comptroller and Auditor General.
The board of FÁS said it accepted Mr Molloy's resignation with regret.
Chairman of the board of FÁS, Peter McLoone, said it was a difficult personal decision for Mr Molloy, which was made in the best interests of the organisation.
The State training agency spent more than €640,000 over four years on transatlantic travel promoting its Science Challenge programme.
Yesterday, Mr Molloy defended spending by the agency.
He said the money was spent developing relationships with the science community in Florida and that the programme was a very good one that had benefitted Irish students.