Supporters of the 80-year-old Immaculata School in the District failed to win approval yesterday from the Montgomery County Council for a plan to save the private school from its scheduled closing this spring by moving it to an abandoned county school building in Chevy Chase.

The council has planned to locate a recreational center at Leland Junior High School, the site that the Immaculata supporters requested. Although the council delayed its final decision until Friday, most members made it clear they joined County Executive Charles W. Gilchrist in rejecting the idea of leasing the building to Immaculata.

Several of the seven council members, including Scott Fosler, Rose Crenca, David Scull and Esther Gelman, said they were eager to see the long-awaited recreation center established and said they feared the school proposal would stand in the way.

"I have the highest regard for Immaculata's educational goals and what they are trying to do here," Gelman said, "but it's not the county's business to save private schools." She said she wanted to help Immaculata, "but not in this school, at this time."

The Sisters of Providence have operated the Catholic high school for girls and its companion grammar and junior high school, Immacula Dunblane, at Tenley Circle NW since 1905. Last October, however, the Roman Catholic order announced that because of a declining number of nuns, it would sell the school buildings to American University to pay for retirement and medical care for its aging members.

The organization of parents seeking to keep the school going at another site was formed one week later. According to leaders of Save Immaculata/Dunblane Inc., about three-quarters of the staff and 500 students have expressed an interest in remaining at a new Immaculata school that would be Catholic in orientation but run by a lay group.

The proposal to move into the Leland building drew objections from county school administrators, who feared racial balance and enrollment patterns at nearby Bethesda-Chevy Chase High School could be disturbed if the private school were to draw students from the public school's population. Also objecting to the plan were the Town of Chevy Chase, the county's recreation department and county planning authorities. All are in favor of a recreation center at the site.

The Immaculata organization has offered to share space with a community center, but county recreation officials said they are concerned programs would clash, especially in the gymnasium and outdoor play areas.

Immaculata officials said they are willing to submit to restrictions on the number of students they could draw from the Bethesda-Chevy Chase area.

Council member Neal Potter proposed a delay so officials could analyze the problems of operating the school and the community center on the same site -- as well as the financial benefits. But even some council members who voted for the delay offered little hope for a solution. "The impossible has to be done," Council President Michael Gudis said, "in a very short time."