Labor Department officials ruled Monday that Prince George’s County schools shortchanged more than 1,000 teachers recruited from foreign countries and ordered the district to pay $5.9 million in back wages and penalties.

School officials recruited the foreign instructors for classes such as math and science that were hard to fill but then required that the teachers cover thousands of dollars in expenses related to getting temporary work visas — expenses that, Labor Department officials said, should have been covered by the system. That violated laws requiring that U.S. and foreign teachers be compensated equally.

Federal officials have labeled the Prince George’s County Public School System a “willful violator’’ of labor laws and could forbid it to get any more temporary work visas, the majority of which were given to educators from the Philippines.

Superintendent William R. Hite Jr. said in a statement that he plans to appeal the findings, adding that they “may have a devastating impact on PGCPS and its employees and the school system’s ability to continue to place a highly qualified teacher in every classroom.”

He said, “This determination penalizes a school system that has strived to obtain qualified teachers in the same or similar manner used by other school systems throughout the country.”

Under the Labor Department ruling, the Prince George’s system owes $4.2 million in back wages to the foreign teachers and $1.7 million in penalties. Federal officials imposed the penalties because school officials “refused to acknowledge” the problem with the back wages and to negotiate a settlement, according to Labor Department spokeswoman Elizabeth Alexander.

This comes as the school district is struggling with a $155 million shortfall that has prompted cutbacks in sports and outdoor education programs, as well as hundreds of potential teacher layoffs.

The district also faces the possibility of legal action in civil courts. Some teachers recruited from the Philippines had hired a lawyer because of concerns they were being treated unfairly during recent budget cuts.

“The point here is that teachers from the Philippines should not be penalized and have the same rights as other teachers,” said Arnedo S. Valera, an immigration lawyer and executive director of Migrant Heritage Commission, a Filipino cultural group based in Fairfax. “This is a good finding to make sure that we are treated fairly, but it’s not over yet.”

Prince George’s began recruiting foreign teachers in 2005 because officials had trouble filling jobs with American teachers who could meet the tougher certification standards imposed by the federal No Child Left Behind law, said Synthia Shilling, the district’s human resources director. Two-thirds of these educators teach in critical areas, such as high school math and science, as well as special education.

The overseas recruiting effort was unusually intense, and the district used the federal temporary work visa, called H-1B, far more often than most school systems nationwide.

A complaint from one of the recruited teachers, lodged in 2007, prompted the federal investigation. It found that 696 foreign teachers used their own money to pay a $500 anti-fraud fee to the Department of Homeland Security. Others paid a $1,000 attorney’s fee and a $3,500 placement fee, among other expenses.

Federal investigators found that 1,044 foreign teachers paid fees that should have been covered by the school district. Prince George’s has nearly 9,000 teachers.

“All employers, including school systems, are required to follow the law. That includes the legal duty to pay every teacher hired the full wages he or she is owed,” Nancy J. Leppink, acting administrator of the Wage and Hour Division, wrote in a statement.

Across the country, several large school systems have recruited teachers from foreign countries in recent years. A 2009 report from the American Federation of Teachers, the second-largest teachers’ union, estimated that there were more than 19,000 foreign teachers working in U.S. schools on temporary visas in 2007. That was up from nearly 15,000 in 2002. (The figures included foreign-trained teachers using the H-1B visas or another temporary visa, called J-1.)

An AFL-CIO report found that in 2008, Prince George’s schools obtained approval for 239 petitions for H-1B visas. Baltimore schools obtained 229 such approvals, the report found, and East Baton Rouge Parish schools in Louisiana obtained 205, Dallas schools 105 and New York City schools 96.

Since 2005, there have been at least 17 federal probes into wage disputes in school districts. More cases are pending, said the Labor Department spokeswoman.

For the past six months, the Labor Department and Prince George’s school officials have tried to reach a settlement. The main issue, officials said, has been the label of “willful violator.” School officials say they have acted in good faith — and didn’t know they had to pay the fees.

“When we were notified by the Department of Labor that we were doing something that was not in accordance with regulations, we corrected it immediately and paid the fees ever since,” said Briant Coleman, a schools spokesman.

Last month, school officials told H1-B visa holders in closed-door meetings that those in non-critical areas, such as social studies, would not get their visas renewed — probably resulting in hundreds of foreign teachers losing their positions between now and 2014.

Staff writer Nick Anderson contributed to this report.