Amid strike threats at Yale and an approaching union preference vote at the University, the Harvard University Employees Representatives Association revealed yesterday it had demanded "a substantial wage increase" and other benefits from the administration.

President of the HUERA Mr. Helen Maynard said the union had applied for elimination of the "three day sick pay" clause and for strict seniority, as well as for the wage increase.

Yale Troubled

In New Haven, meanwhile, the independent Federation of Yale University Employees voted to strike, following a breakdown in negotiations yesterday.

Maids and janitors face an impending preference vote between the HUERA and the AFL affiliated Building Service Employees International Union within the next week. The state labor relations board meets tomorrow to set a definite date.

Mrs. Maynard said the union based its wage demands on the present scale of living. "The cost of living has not come down enough to affect our wages," she stated.

"We have never made a reasonable demand that the University has not come through on," she added. "We are not asking for the world on a platter."

The University and the HUERA have until June 30 to reach an agreement. The present contract runs out at that time.