The principal of the city’s most elite elementary school departed suddenly this summer, leaving the school without a permanent leader as it prepares to open in a new location.

Brian Culot, principal of the Anderson School since 2006, announced just as school was ending for the summer that he would not return this fall. Instead, he is taking over at Cottage Lane Elementary School in Blauvelt, N.Y., which is near his Rockland County home.

“It was a shock,” said Judi Aronson, until today Anderson’s network leader in the empowerment schools organization. As the community superintendent for District 3 in the 2005-2006 school year, Aronson helped bring Culot to Anderson from a downtown elementary school.

Culot’s announcement came at a particularly tumultuous time for the school, which was preparing to move seven blocks south into the MS 44 building on the Upper West Side. The move, which took place this month, was part of a contentious plan to alleviate overcrowding by relocating several schools in the neighborhood, some against their will. Anderson never opposed its move, which will allow it to expand slightly but also requires it to share space with a middle school that is being closed due to poor performance.

With the move now complete, Aronson said parents at the school, which admits only top scorers on a citywide gifted exam, had turned their attention to finding a replacement for Culot. (The building is still “an absolute mess,” she said.) The first round of the search is over and a hiring committee will soon evaluate candidates Aronson helped recruit, she said.

“I was very impressed by the parents,” she said. “They were very anxious. … They could have taken the anxiety and become very angry. But they’ve been incredible.”

It used to be common for city principals to be hired away by suburban school districts. But changes to the pay scale for principals helped reduce incentives for them to leave the city.