Science Foundation Ireland's director general William Harris is to leave his post at the body next summer.
He has accepted an appointment at California Polytechnic State University in the US and will leave SFI in July 2006.
Dr. Harris was appointed as director general in September 2001 on a five-year contract. Before coming to Ireland, he had previously served at the US National Science Foundation.
Science Foundation Ireland invests in academic researchers on behalf of the Government.