The money the NSW government will spend on a new bilingual program in primary schools would be better spent on special education, the NSW Teachers Federation says.

Four schools will trial a state-funded bilingual program next year to boost the study of Asian languages.

Students will be taught in a foreign language - Mandarin, Japanese, Korean and Indonesian - for 90 minutes a day.

In 2010, participating schools will include four government primary schools - Rouse Hill Public and Murray Farm in Sydney's northwest, Scotts Head Public on the North Coast, and Campsie Public in Sydney's inner-west.

Kindergarten and Year 1 students will initially be given bilingual instruction, with plans for all grades to eventually be included, Education Minister Verity Firth told The Daily Telegraph.

"By the completion of primary school, the students will have a solid foundation of the language and it's expected they will continue their learning into high school," she said.

The NSW government has committed $2.25 million over four years to the program.

But Teachers Federation president Bob Lipscombe says the money could be better spent on other education programs.

"There's a considerable need for additional resources for our students with special needs in our schools and one would be very concerned if this program represents the diversion of funds from that sort of area," he told reporters on Wednesday.

Mr Lipscombe said that if the state government was offering language programs, all NSW students should get them.

"We're supportive of language programs in schools but we believe they should be made available to students across the state, not confined to a small number of schools."