Metro will have to borrow money early next month to meet its payroll if Fairfax County continues to withhold more than $11.2 million in operating subsidies because of a fight it is having with Metro over accounting procedures.

The first fight broke into the open yesterday during a sometimes heated closed session of the Metro board. Before Fairfax releases the money, County Executive J. Hamilton Lambert told Metro in a letter the county is insisting among other things that Metro guarantee in writing that the county's subsidies to Metro will not exceed the estimated subsidy by more than 2 percent.

The practical effect of that requirement could be that in a year of unusual inflation Metro would either have to stop operations or other local governments would have to pay Fairfax County's share.

"There's no way [Metro General Manager Richard S.] Page could sign that kind of pledge for just one jurisdiction," Alexandria Mayor Charles Beatley said. The county's proposal "is not a proper action for Page to participate in," he said.

Beatley and other area officials agreed, however, that Fairfax County is properly concerned about Metro's seeming inability to accurately predict the impact of Metro subsidies in each of the eight local governments that support the transit system. The Fairfax complaint had it origin in June when Metro adjusted upward by $2 million the estimated subsidy the county would have to pay during the current fiscal year.

Metro has done a fairly accurate job in recent years of estimating total cost and subsidy for the bus and subway systems. The problem has come in predicting the way subsidies and revenues would be divided among the eight local governments. In that process Metro has not done as well.

Marie Travesky, a Fairfax County supervisor and alternate member of the Metro board, charged yesterday that Metro's good performance on estimating total system subsidies might occur because "sometimes Metro carries cost from one year to the next." Asked if she was suggesting that Metro was fiddling with the books, she said, "I'll stand on my comment."

Page said he did not know what Travesky was referring to. "We are audited by independent outside auditors and that audit is available to the board of directors," he said. He added that there are some anomalies in Metro's financial procedures, including a wonderful provision thought up several years ago and enthusiastically endorsed by local governments that permits them to postpone paying for two years all subsidy overruns. Fairfax County,and some other governments, are now anxious to get on a pay-as-you-go basis.

Arlington County has also threatened to withhold subsidy payments beginning in January until Metro management moves toward more effective cost controls.