Edward A. Curran, director of the National Institute of Education, left his job yesterday over what a top aide said was a disagreement with Education Secretary Terrel H. Bell about the future of the educational research unit.

"He was fired and I resigned," said the aide, Larry Uzell.

Uzell said Curran's dismissal was the culmination of an escalating dispute between the NIE director, who favors abolishing the institute, and Bell, who opposes doing away with NIE.

A spokesman for the department confirmed Curran's departure from the job he took last October, but said, "It's my understanding he has resigned." Other Education officials declined comment, and Curran could not be reached.

NIE has long been a target of conservative attacks because of its alleged bias toward liberal research. Curran, the former headmaster of Washington's National Cathedral School nominated by President Reagan last August, attempted to change that. Recently he circulated proposals for grants to study conservative themes--including tuition tax credits and the "effects on learning of a schoolchild's mother's holding a full-time job"--and terminated a number of long-time research contracts.

Curran's proposals have, in turn, prompted outcries about attempted politicization from the education research community.