A federal judge in Alexandria has ruled that Fairfax County must pay its fire and rescue service lieutenants overtime at time and a half, a practice the county has fought and one that now could cost thousands of dollars in back pay.

The decision came at a time of belt-tightening and budget worries for the county. Officials said they would not know the financial impact of the ruling until they analyze the order handed down late Friday by U.S. District Judge T.S. Ellis III.

In addition to his ruling, Ellis ordered meetings this week for representatives of both sides on how much to award the lieutenants. County officials would not comment on whether they will appeal Ellis's ruling.

"It is premature to speculate what the county will do," said Richard A. King, deputy county executive for public safety. King also said he "would not speculate" on the amount of money the lieutenants may be awarded.

The lawsuit, filed last year, argued that lieutenants should be paid overtime in the same way as fire and rescue personnel of lower rank.

The county has paid the lieutenants straight time for any overtime worked, contending that they were classified as executives under federal regulations and thus excluded from earning the extra half-time premium. Employees ranked sergeant and lower were paid time and a half.

Under that system, the lieutenants argued, sergeants were able to earn more money overall than they were when overtime was included.

Ellis rejected the county's arguments, saying that the lieutenants are not executives because they are paid hourly, not straight salaries, and therefore should be paid the overtime premium.

David Holland, a spokesman for the lieutenants, said the amount of the award probably would be in the thousands, rather than millions, of dollars. "Lieutenants don't work a lot of overtime," Holland said.

Seventy-eight current and former lieutenants originally brought the lawsuit against the county. According to Holland, a lieutenant generally makes between $35,000 and $50,000 a year.

Damages for the lieutenants could be retroactive as far back as three years before the suit was filed, if the lieutenants can prove to the court that the county willfully violated federal law in not paying the full overtime amount, according to the lieutenants' attorney, Gregory K. McGillivary.

If not, the lieutenants probably would be awarded back pay for two years prior to the date of filing, McGillivary said.