The Antioch school district's three-year affiliation with an education reform foundation aimed at improving schools through better governance has been severed.

In a letter dated June 1, the Center for Reform of School Systems, which is supported financially by the philanthropic Broad Foundation, announced that it was ending the Antioch school district's participation in its Reform Governance in Action program.

The reason given: The May resignation of Superintendent Deborah Sims, an alumnus of a Broad training program.

In the sharply worded letter that praised Sims' leadership and criticized the school board, CRSS founder Donald McAdams said the foundation was not interested in continuing the relationship in the wake of the superintendent's departure.

"Your governance team has changed — Dr. Sims is no longer your superintendent — and the board in recent months has not had a sharp focus on student achievement," he wrote.