School officials in Montgomery County were ready to begin remodeling Rosemary Elementary School next Monday and move books and equipment from North Chevy Chase Elementary to Rosemary.

However, their plans came to an unexpected halt yesterday when, in a rare move, the acting Maryland superintendent of schools ordered the Montgomery County Board of Education to halt current pupil assignment plans for those two schools and Montgomery Blair High School.

The superintendent's action was another chapter in an increasingly convoluted situation that one high-ranking state employe called the most complicated since the county school board tried to comply with the 1954 Brown desegregation case.

In an effort to adjust to declining pupil enrollment, the local board voted last November to close Rosemary Hills and change the attendance boundaries of Blair High and Eastern Intermediate schools. Parents of children who would have been affected appealed and, after a long process, the state board of education rejected all three decisions, ordering the local board to come up with better solutions.

On July 28, the board decided to close down the magnet program at North Chevy Chase and move it to Rosemary Hills. The board also decided to delay action on changing Blair High School's attendance boundaries until November, after the elections.

Acting state superintendent Joseph L. Shilling granted a stay of those solutions until communities have a chance to challenge the plans before the state board of education on Aug. 19.

"I feel elated," said Marla Fogelman, one of several Rosemary Hills area parents who have an interest in seeing the school return to a pairing in which children attend Rosemary Hills for years K-2 and Chevy Chase Elementary for the next four years. "The state board is going to listen to us and they know which side is right."

But Montgomery school board member Marian Greenblatt said the situation was an intolerable intrusion into the local board's authority.

"These decisions were the best compromise under the circumstances," she said. "This interference from the state level is totally unwarranted."

Ellen Heller, a state assistant attorney general who handles the state board's legal matters, said the nine-member panel can decide to uphold, modify or reject the local board's actions on Blair, North Chevy Chase and Rosemary Hills.

The state board must yet decide five other appeals of county school closing decisions from last November, and the local board is challenging the state board's reversals of its Rosemary Hills, Eastern and Blair decisions in the Circuit Court.

As the decision stands now, pupils who would normally go to North Chevy Chase won't know where they will attend school this fall until nine days before school starts.