Another 90 people could be made redundant at the North Eastern Education Board because of budget cuts.
Planned reductions are unrealistic if services are to remain effective, the board warned.
It faces cuts worth more than £3 million this year and many schools could be in severe difficulties if they do not try to make savings, chief financial officer Hubert Taylor said.
"To make some of the expenditure savings in our central budget required by the Department of Education we would need to make a further 90 people redundant, on top of the 29 voluntary redundancies last year," he said.
"That equates to over a third of headquarters staff and this is not realistic if the services provided are to remain effective."
This year is expected to be the worst of the four-year budget cycle for board services funded through a centrally held allocation of Government money. The largest cut will come from the central schools budget at just over £1.5 million.
Maintenance and curriculum support will lose a tenth of their budgets while headquarters services will have to save £220,000. The school library service, home to school transport, special education and school meals will all suffer from reduced funding.
An Education Department spokesman said: "Following budget 2010 being agreed by the Executive, allocations for 2011-12 were issued to Education and Library Boards in April with spending and savings plans being commissioned.
"Boards were given clear guidance on the areas to be targeted for savings and those to be protected. The minister recognises that the budget settlement represents a challenge for all those in education.
"The department has engaged with boards over the budget planning process providing advice and clarification as needed. It has emphasised however that the quantum of resources available to education in 2011-12 was determined by the decisions of the Executive as a whole and is unlikely to change."