After four years of rising test scores that drew national attention for Charlotte-Mecklenburg Schools, achievement levels dropped broadly this past school year - particularly in high schools.

CMS leaders said Thursday that they couldn't pinpoint any single cause, but they suggested the budget cuts and ballooning class sizes of recent years didn't help.

The bad news arrives at a pivotal moment for CMS, which is losing the services of former Superintendent Peter Gorman and three veteran school board members.

Gorman resigned in June, and the three board members - Kaye McGarry, Trent Merchant and Joe White - aren't seeking re-election this November.

New state exam results show scores declined in 15 of 22 areas tested. The picture looked especially dim in high schools, where biology was the only subject out of eight tested where scores didn't fall.

Biology scores stayed flat, while scores dropped in Algebra I and Algebra II, English I, History, civics and economics, physical science and 10th grade writing.

"Considerable regression," Interim Superintendent Hugh Hattabaugh called the results. "We're not happy about that. We'll be determining what we can adjust next year."

There were bright spots: The district improved its graduation rate, from 69.9 percent to 72.2 percent, and also showed gains in science, particularly in grades 5 and 8.

Under Gorman, the district won national notice for its rising scores. CMS is a finalist for the $1 million Broad Prize, awarded annually to the urban school system showing the greatest success improving performance and narrowing the achievement gap.

But CMS' new results showed the gap between poor students' math scores and those of wealthier children grew by 2 percentage points last year.

CMS has been budget-cutting for the past few years. Last year it closed about a dozen schools and issued pink slips to hundreds of teachers, only to restore many of those positions after receiving a $26 million infusion from Mecklenburg County.

Hattabaugh said he couldn't attribute the declines solely to the budget cuts, "but we think it's always a good idea to look at the context when it comes to scores."

Others pointed the finger directly at falling school funding.

All the talk of layoffs and school closings demoralized teachers and affected the test scores, said Harold Dixon, Mecklenburg PTA Council president.

"This was not surprising," said Doug Swaim, co-founder of MeckFUTURE, a parents' group that rallied to help CMS during its budget crisis. "These cuts are finally showing up in the test scores."

Others blamed more than 50 controversial new local tests CMS rolled out this spring. They suggested those tests took away too much class time and distracted schools.

Chris Cobitz, CMS' top testing official, said students who took the local tests did so after the state tests had been completed.

South Mecklenburg High Principal Maureen Furr said her school achieved its goals, but only through herculean efforts from teachers. She said she had 2,000 students last school year, but only three administrators to support teachers.

Many South Meck classes included 30 or more students; some ballooned above 40.

"We need to reduce class sizes - that is incredibly important," added Bill Anderson, head of the nonprofit group Mecklenburg Citizens for Public Education, or MeckEd.

Hattabaugh said he expects a net increase of teachers next year, compared to the past school year. The Observer has asked for a detailed final tally of positions lost and gained in the budget shuffle, but the report hasn't been released yet.

Also falling was the number of schools hitting annual progress goals tied to the federal No Child Left Behind law. Just 28 percent of CMS schools met their goals.

Fifty-eight percent did last year. District officials pointed out that the state raised the bar this year, as it periodically does to stay in compliance with federal standards.