A new church school in Kensington will admit a maximum of 20 new students a year from the surrounding public schools, in an effort to calm fears that it would interfere with a public school integration plan, its minister said yesterday.

In a letter to Montgomery County Executive Charles W. Gilchrist, the Rev. William R. Wooten Jr. of Grace Episcopal Church said the church had no desire to "interfere with any community racial balance" and said enrollment would be restricted for at least three years.

Gilchrist was criticized earlier this week by County Council President David Scull and the county's NAACP chapter for his decision to lease the closed Larchmont Elementary School to the church, which already operates a church school in Silver Spring. About one-third of the students at the Grace school in Silver Spring, which goes from kindergarten through second grade, are minorities.

Critics of the action said opening a private school would exacerbate problems of sagging enrollment at nearby public schools. After a school board decision in March to revise an integration plan in the area, more than two-thirds of the parents of kindergarten-age children in the Chevy Chase Elementary School area, most of them white, said they would not enroll their children at Rosemary Hills Elementary School in the fall.

The Larchmont building, which will be used for grades three through six, is about half-a-mile from North Chevy Chase Elementary, at which, along with Chevy Chase, public school students in grades two through six attend.

"We regret the concerns that have arisen regarding this matter," Wooten wrote, adding that it is the church's desire "to cooperate in assuring strong, equal and meaningful education for all children."

Scull, however, said that even 20 students could have a serious impact on nearby public schools. "I appreciate the helpful intent, but I'm not certain that that will solve the problem," he said.

"The county government has no business setting up opposition to its own schools," Scull said, adding that private school campuses should "absolutely not" be added in areas such as Kensington, "where decisions are being made whether to attend public or private schools."

Roscoe R. Nix, president of the Montgomery County chapter of the NAACP, agreed with Scull that the church's promise to limit enrolement leaves little changed. Nix, a former school board member, said he did not question the integrity of the church but rather the wisdom of Gilchrist's decision to sign over to the church school buildings "in the midst of a cluster where there has been a lot of tension, and threats by people that they will take their children out of public schools."

Nix said if Gilchrist cannot be persuaded to reverse his decision, the NAACP will ask church officials to change their plans voluntarily.

In a letter to Nix sent yesterday, Gilchrist said plans to lease the school to the church went through public hearings in April without opposition from the public school system or the NAACP. He said he is willing to listen to discussions on county policy of leasing to private schools, but added that "on the basis of what I now know, I am not prepared to break the contract with the Grace Episcopal Church."