United States regional airlines have a hard time finding pilots because of low wages and new rules mandating more experience for entry-level aviators, according to a government study published on Friday, according to the Associated Press.

The U.S. Government Accountability Office, which analyzed data on pilots from 2000 to 2012, said 11 of 12 regional carriers it interviewed for its study had problems meeting their hiring needs, the AP reported.

The report added that while bigger airlines did not report similar difficulties finding pilots, they were still concerned that problems faced by regional partners could affect their ability to provide flights to some areas, according to the AP.

U.S. Federal Aviation Administration rules that took effect last year require co-pilots, or first officers, to have 1,500 hours of flight time to operate commercial jets, up from 250 hours previously, the AP reported. Airlines also must give pilots more rest under separate U.S. rules that took effect this year.

The study comes as some regional carriers have voiced concerns about a pilot shortage because of the new requirements, according to the AP.

Earlier this month, Republic Airways Holdings said a scarcity of qualified pilots would hurt pretax income as it cuts its planned flying, the AP reported. The company said the beefed-up experience requirements were limiting the pipeline of employable candidates.

"When we talked to the regionals, there were a number that indicated they were having a more difficult time now than in the past of getting candidates that met their standards," said Gerald Dillingham, director of civil aviation issues at the GAO, according to the AP.

He added that regional airlines were working to boost the employment pipeline by forming partnerships with pilot-training schools and offering tuition reimbursement for students, the AP reported.

In its report, the GAO said the number of pilots certified to fly looked large compared with the number employed, according to the AP. The agency said FAA data showed more than 137,600 pilots under age 65 had Airline Transport Pilot certificates in early 2014, compared with more than 72,000 who were working at airlines in 2012.

About 5 percent of pilots with ATP certificates and 14 percent of those with U.S. commercial certificates had a foreign residence, the agency said, citing FAA data, the AP reported.

The Air Line Pilots Association, the largest U.S. pilots union, has expressed concern that the pay scale at domestic airlines discourages qualified applicants, according to the AP. It said in a statement earlier this month that pilots' salaries at 14 regional airlines started below $22,000 a year.

The union added that many U.S. pilots chose to work for foreign carriers such as Emirates, where new co-pilots are paid $82,000 a year and receive housing benefits, the AP reported. That compares with $61,000 for co-pilots at Delta Air Lines Inc and United Continental Holdings Inc, the union added.

The GAO study also said fewer people were enrolling in and completing pilot programs. It said low wages for entry-level pilots, rising education expenses, limited financial help and "a perceived lack of stability" in the industry accounted for the profession's decreased appeal, based on feedback from officials at schools that provide training, according to the AP.