SANFORD — The Sanford School Committee decided Monday night to stop offering single-gender classrooms for middle-schoolers.

The sixth grade at the Willard School has comprised one all-girl, one all-boy and four co-ed classes for the past three years. The same structure was instituted at the fifth-grade level this year.

The American Civil Liberties Union of Maine sent a letter to the district last month demanding that the district stop offering the single-gender classes, saying that the program was based on gender stereotypes and violates federal law.

The ACLU cited the all-girls class discussing current events over cocoa and the boys class earning  points toward prizes from the National Football League by getting more exercise as examples of perpetuating “improper” stereotypes.

Superintendent David Theoharides said in a press release Monday that the district decided to suspend the program indefinitely because it did not want to engage in litigation threatened by the ACLU.

He said the district does not believe the program violates the law and believes it is beneficial for many students.

The ACLU applauded the decision to end the program, which it said in a press release “was based on harmful gender stereotypes.”

Zachary Heiden, the ACLU of Maine’s legal director, said in the release, “Children have the right to be educated based on their needs as individuals, not based on their sex.”