Less than 45 percent of Prince George's County students who took Maryland's new high school English test passed the exam last spring, while Howard County's 77 percent passing rate was the highest in the state, according to data made public yesterday.

Seven of 10 passed the test in Montgomery County, and all other school systems in Washington's Maryland suburbs exceeded the statewide passing rate of 57 percent.

Most students who took the test were sophomores, and they faced no individual consequences for failure. But that will change in the spring of 2007. The 10th-grade students who take the test then must pass it or risk failing to earn a diploma when their class graduates in 2009.

By that year, Maryland students must pass tests in English, algebra, biology and government or at least earn a minimum score in each subject and a combined passing score for all four.

State education officials predict that scores will rise sharply when students buckle down to graduate. Ronald A. Peiffer, deputy state superintendent for academic policy, said the high stakes could boost scores by as much as 30 percentage points.

Maryland's English scores show "that we are at a very good, what I would call a starting point," said Adam Milam, testing coordinator for public schools in Anne Arundel County, where 61 percent passed. "This is base line for us."

Milam predicted steady gains in English in coming years. "From the feedback that I get," he said, "it is one of the most challenging of the four High School Assessments."

Passing rates were 60 percent in St. Mary's County, 62 percent in Charles County, 67 percent in Frederick County and 69 percent in Calvert County.

The test results helped round out the picture of how many schools in Maryland are making adequate progress toward the achievement, attendance and graduation-rate goals of the federal No Child Left Behind law. State data show that 1,042 Maryland schools reached the federal standard in the 2004-05 school year and that 390 did not.

In all, 241 Maryland schools are on a watch list and labeled as needing improvement, down from 255 the previous year.

The new total includes 77 high schools identified yesterday. Among them are 31 in the Washington area: five in Anne Arundel, five in Montgomery and 21 in Prince George's.

None were in Frederick, Charles, Howard, St. Mary's or Calvert.

Some high schools landed on the watch list for low scores posted by a sliver of their student populations, such as disabled students in special education programs. Others on the list, including Gaithersburg and Montgomery Blair high schools in Montgomery, made adequate progress in the last academic year but, under federal law, must replicate that performance to move off the list.

Many other schools remain on the list, year after year, with substandard test scores.

"We are starting to see, and our school systems can see, places where there are significant problems," said Gary Heath, assistant state superintendent for accountability and assessment.

No Child Left Behind ratings were announced several weeks ago in Virginia, where 322 of the state's 1,820 schools did not make adequate yearly progress, or AYP, a spokesman said. In the District, 70 public schools, or nearly half the system's total, failed to make AYP for reading and math, data show.

The new Maryland English test updates exams given in recent years. It is longer than previous tests, with two one-hour sessions and one of 50 minutes. Measuring grammar, composition and reading comprehension skills, it includes multiple-choice questions and others requiring brief or extended written responses.

Staff writers Lori Aratani, Daniel de Vise and Ylan Q. Mui contributed to this article.