The change reverses a DOE decision in March when about 1,500 to 1,700 substitutes were told they wouldn't be allowed to teach in public schools next year because their qualifications do not meet new federal standards.

Now they have until June 30, 2006, said department spokesman Greg Knudsen.

Substitutes were told of the decision, which was made "after much review and discussion," in a letter sent to area superintendents from Assistant Superintendent Claudia Chun.

To qualify for continued employment, Chun said the substitutes must have satisfactory evaluations, be on a school's preferred substitute list, complete a new 30-hour training course and be on track to complete a bachelor's degree by June 30, 2006.

"We recognize the important role that all of our substitute teachers have in the education of public school students and appreciate their dedication to students," Chun said. "Training and degree requirements are means of having qualified teachers for our students."

The original March decision would have meant about 28 percent of the substitute teacher work force would not qualify to renew their registration with the DOE because they do not hold bachelor's degrees.

Knudsen had said the school system must tighten the requirements because of provisions in the federal law known as the No Child Left Behind Act.

The substitute teachers disputed the DOE's interpretation of the federal law and the timeline issued by DOE.

The DOE is facing an estimated 1,600 teaching vacancies each year.

The DOE has about 13,000 regular schoolteachers but uses an average of 1,000 substitutes per day statewide.

The No Child Left Behind Act requires that by the 2005-06 school year all teachers must be "highly qualified," which generally means they must be certified and demonstrate mastery of the subject they teach.

Starting this school year, all new teachers hired with federal money are supposed to be highly qualified, according to the law.

Also by the 2005-06 school year, all school paraprofessionals ­ educational assistants and others who help in the classroom but are not in charge of it ­ are supposed to have at least two years of college.

This wasn't the first skirmish that the public school system and substitutes have had recently. Substitute teachers are trying to form their first labor union and have had several disputes over pay rates in the last year.