Federal regulators have granted Virginia and Maryland new flexibility in enforcing the No Child Left Behind educational standards -- changes that could keep some schools from facing sanctions later this year.

In Virginia, the move ended five months of conflict between state and federal education officials over how best to apply the complex law in the commonwealth, but it did not satisfy Board of Education President Thomas M. Jackson Jr., who had asked that the state be exempt from even more of the requirements.

In a statement, he called the federal decision "at best, halting progress" and said the U.S. Department of Education "continues on a course that undercuts support for [No Child Left Behind] . . . and encourages confrontation."

State officials in Maryland, who have been less critical of the law, said yesterday that they also have won permission from the federal government to loosen slightly their school accountability rules.

Ronald A. Peiffer, Maryland's deputy superintendent for academic policy, welcomed the change. "If you're going to have an accountability system, you have to have it measured accurately and fairly," he said.

No Child Left Behind requires that students take math and reading tests each year in grades 3 through 8 and in high school. By 2014, all students must be proficient. Until then, schools must show they are making adequate yearly progress. Test scores for groups of students, including racial minorities, low-income students, children learning English and those in special education classes, are published separately and also must rise. Schools that do not show progress for two consecutive years face such sanctions as allowing parents to transfer their children at the district's expense.

In January, Virginia's Board of Education asked for waivers from 10 areas of the law, and it has since asked for two more. On Monday, the U.S. department granted four of those requests, state officials said. Five others were rejected and three are still under review.

Virginia's new flexibility comes in the complex formula for deciding whether schools and school districts are making yearly progress. One of the most significant changes will give credit to students who fail a state Standards of Learning exam but then pass an exam in the same subject. A request to count the second tests had been denied.

Maryland's change comes in the issue of testing special education students. It will allow educators in some cases to exclude some disabled-student test scores when judging whether schools are making adequate yearly progress.

Virginia educators and politicians have been among the most vocal in a national outcry that No Child Left Behind has been a costly and confusing federal burden for local schools. The state's General Assembly voted in February to study how much federal funding the state would lose if it were to withdraw from participation entirely, a step that has been explored in other states.

In his statement, Jackson complained that Virginia has waited too long for answers, especially because some of the requests were similar to those already granted to other states. Texas and Oregon both learned in 2004, for instance, that they would be permitted to allow students to take tests more than once and count only their best score.

"This continued disrespect toward a state that has faithfully implemented the No Child Left Behind Act of 2001 is bewildering," he wrote.

Susan Aspey, a spokeswoman for the U.S. department, responded that regulators "spent a great deal of time working with the state's education leaders, so these claims are perplexing at best."

As complaints about the law have mounted, negotiations between the states and the federal department have been intense, especially since Secretary of Education Margaret Spellings announced in April that she was looking for ways to give states new flexibility.

"She's doing a balancing act," said Jack Jennings, president and chief executive of the Center on Education Policy and a supporter of the law. "How far must she go to relieve political pressure without giving away the essence of the federal law?"