The Montgomery County school board decided this week to allow interscholastic sports to resume this fall in the seventh, eighth and ninth grades.

Interscholastic sports were eliminated this past year to save money. In addition, some board members and school administrators had argued that competitive sports turned junior highs or middle schools into "mini-high schools" and that intramural sports would be better for junior highs.

The school board, according to officials, has received much mail from students arguing that interscholastic sports are a source of school spirit.

After the County Council granted funds in May for interscholastic sports in the intermediate grades, the school board decided to have sports in the ninth grade but hesitated on allowing sports in the seventh and eighth grades.

In its decision this week to fund sports for the seventh and eight grades, the board set up a plan of monitoring the program. A decision on whether to continue the sports program will be made in two years, before budget requests are made for fiscal 1981.

The board was told by Henry Heller, head of the Montgomery County Educators Association, that if interscholastic sports were eliminated, the contract with the teachers would be breached since the contract calls for stipends for junior high teachers who coach sports.

"This is a satisfactory resolution given the legal opinions we've had (on possible problems with the teachers contract)," said board member Blair Ewing. "It's important to note that interscholastic programs in middle schools are problematic."

David Naimon, the high school student who is a speaking but nonvoting member of the school board, said the junior high school students were "very excited about it. All this year junior high school students were advocating interscholastic sports for all the grades in junior high," said Naimon. "But I don't think they'll be too happy when they find out about the fact that it's being studied for two years. It sounds like two years and out."

But board member Marian Greenblatt, who abstained from voting on the interscholastic sports issue, said the study plan is not feasible. "Once you put it there for two years, it's very difficult to take it out," she said, "It's there."

Heller said the teachers' association did not consider sports being dropped last year as a violation of the teachers contract because "there wasn't money. The board was taking money from the interscholastic sports program to fund another item of the negotiated contract - the full cost of living raise.