The Atlanta school board scuttled a planned vote Monday that would have launched an experiment to expand an elementary school to include middle school grades 6-8, a model that could be replicated in other city schools.

Centennial Place Elementary School in Midtown would have become the system’s first traditional school to convert to a charter school, giving it flexibility to add the middle school grades and set academic priorities.

The vote was delayed until a later meeting on the advice of the board’s attorney, Bill Prescott. Centennial Place’s teachers and parents had approved slightly different versions of the school’s petition to convert to a charter school, but Prescott said state law requires both teachers and parents to vote on the same petition. A new vote by Centennial Place’s parents will be scheduled.

A few board members said they were worried that other schools would follow in Centennial Place Elementary’s footsteps and petition to become charters, which already enroll about 1 in 12 Atlanta students.

“My concern is that it seemed like the charter people are running everything, and I’ve got a concern about that because Georgia in recent years seemed to be anti-public school and more for vouchers and charters,” said board member Emmett Johnson. “Where are we heading with this, with conversion charters and charters, period?”

Another Atlanta elementary school is also seeking to teach students from kindergarten through eighth grade, without becoming a charter school. The school board plans to vote at a later date on expanding Toomer Elementary in eastern Atlanta while keeping it under the school district’s direct management.

The two K-8 programs would allow the school district to evaluate whether students perform better in K-8 schools and compare whether the governance structure of the schools matters, said Superintendent Erroll Davis.

Parents overwhelmingly approved Centennial Place’s charter conversion in an effort to strengthen its emphasis on science, technology, engineering, arts and math, said parent Janet Kinard.

“This enables us to decrease class sizes in grades where it’s most important and to restructure our school day based on our needs, like if we need more time for math,” said Kinard, who has a daughter in fifth grade at Centennial Park.

Middle schools are meant to ease the transition to high school and separate big kids from small students, but supporters of Centennial Place’s conversion said older students would be located in a different building and academic results would improve.

“I’m excited about going to K-8,” said Angel Parks, who has a son in second grade at the school. “Each grade level understands the grade under them is looking up to them.”