TORNILLO, Texas (AP) _ School officials have asked parents to discipline their children if they are caught speaking Spanish at school as part of a campaign to improve grades, the superintendent said Wednesday.

''We're not out to start some kind of controversy,'' said Francis Brooks. ''The only thing we're looking to do is help our kids do a little better.''

Brooks said he mailed about 370 letters on Wednesday, one for each child in the Tornillo Independent School District, asking parents to voluntarily sign a contract.

''If you sign and return this letter, you are saying that you will discipline your child if we report him or her for speaking Spanish at school,'' the letter says, in part. ''If you do not sign, nothing will be done to your child for speaking Spanish.''

The letters, in Spanish and English, say the campaign's aim is to try to improve test scores and the English-speaking ability of students.

Tornillo students generally score below state and national averages on standardized tests in mathematics, reading and language skills. The school district teaches English as a second language but cannot afford specialized bilingual-education teachers, Brooks said.

About 95 percent of the children in the school system are Hispanic and about 40 percent speak only Spanish or very little English, Brooks said. An estimated 60 percent of parents in Tornillo, a farming community about 30 miles southeast of El Paso, don't speak English at all, he said.

Federal and state laws prohibit schools from punishing children merely for speaking a language other than English, so the school system is trying to enlist the parents' assistance, he said.

''For the kids' benefit, they must be able to speak English,'' said Brooks, adding that he is not against children being bilingual. ''I'd give anything if my kids were bilingual.''

He said his daughter, 17, and son, 15, barely communicate with their 80- year-old maternal grandmother, Brooks' mother-in-law, whose first language is Spanish.

The idea was mentioned at the February meeting of the school board and was presented to parents at the March and April meetings of the Tornillo Parent- Teacher Organization, he said.

''We did not have any negative comments from parents,'' Brooks said.

Parent-teacher meetings have been conducted in both languages for eight years to encourage more Spanish-speaking parents to attend, said Brooks, who was high school principal in Tornillo before being named superintendent in 1980.

''If it helps encourage students, teachers should speak English only to the kids,'' parent Maggie Zavala told the El Paso Times. ''That way they can learn (English) faster.''

Maria Elena Flood of El Paso, a member of the state Board of Education, told the newspaper she does not object to the Tornillo campaign if it is designed to help children learn English.