A City Council committee voted last week to approve the sale of $53 million in revenue bonds for American University to finance a long-planned sports center and purchase the nearby Immaculata School.

The university and citizens groups worked together to resolve residents' complaints about the proposed sports center, but now citizens are concerned because the university says it has no specific plans for the 8.2-acre Immaculata School at Wisconsin and Nebraska avenues at Tenley Circle.

"We have no idea what they plan to use the property for," said Ruth Dixon, chairman of the Wisconsin Avenue Corridor Committee, an umbrella organization of 22 associations and citizens groups that monitors planning and zoning issues in the Wisconsin Avenue area. "One of the fears we have is more dormitories on the property, and if they expand it could easily have an adverse effect on our residential neighborhood."

She added, "All we are asking is that they involve us and inform us of their long-term plans, just as they did with the sports center. I think the council should want to know the plans before they pass any bills; it seems to us the council is working backward."

American University officials said, however, they have made no final decisions about the Immaculata property, but generally the planned uses include "classrooms, student housing, and other academic uses."

The Sisters of Providence, an order of Catholic nuns, have agreed to sell Immaculata Preparatory School, a high school for girls, and Immaculata Dunblance, a grammar school and junior high, to the university for $7.6 million. Settlement and transfer of the property, about a mile from the university campus, will take place shortly after the two schools close in June 1986, according to the Catholic order and the university.

The council's Finance and Revenue Committee approved the bond issue after members defeated an amendment offered by council member Betty Ann Kane (D-At Large). That amendment asked that the bond issue be reduced by $15 million "because no specific plans for the Tenley Circle property have yet been made public."

University officials had estimated the cost of buying the school site, renovating and equipping it at $15 million.

If the bill is passed by the full council and signed by the mayor, the city will sell the bonds and give the university $53 million in cash. The university will be responsible for repaying the bonds with interest.

The university prefers borrowing the money it needs through the sale of bonds rather than going to a bank because the interest rates on the bonds are lower than the rates charged by banks. The university will enjoy a large saving.

Last month the D.C. Board of Zoning Adjustment sent written approval for the proposed Adnan M. Khashoggi Sports Center on the American U. campus. The center will hold 4,500 spectators for basketball games and 6,000 for concerts and graduation ceremonies. The center, which also will include a swimming pool, a student bookstore and a bank, will cost the university an estimated $19.5 million.

Adnan M. Khashoggi, a billionaire Saudi financier, has pledged $5 million to the university for the center, but American U. Vice President Donald Myers said Khashoggi's donation and others will come over a long period of time and will be used to repay the principal and interest on the bonds.

The remainder of the $53 million will be used to refinance existing university debts, officials said.