The Prince William County Board of Supervisors yesterday enacted an ordinance that will place the first, limited local controls on cable TV operations in the county.

In a unanimous vote, the seven-member board ended a year of jockeying by approving the ordinance, which becomes effective Jan. 1.

Until yesterday's vote, Prince William County was one of the largest areas in the nation that had chosen not to regulate the cable TV industry. The new ordinance contains consumer protection measures to regulate billing, maintenance and service.

In a work session last week, however, the board deleted a number of sections in the ordinance that would have required the county's five cable companies to provide additional service, such as public access channels and the construction of studios for local programming.

Cable television representatives in the county yesterday called the ordinance a victory for the industry, which had lobbied against proposals for a tougher law.

Cable representatives also warned however, that despite the modifications of the ordinance, it still will force cable companies to raise their prices. C. Lacey Compton, Jr., attorney for Prestige Cable, said the ordinance will force "at least a 10 percent" rate hike.

County Attorney John Foote argued that the ordinance could not be blamed for sharp rate increases. "In my judgment that's poppycock," Foote said of Compton's assessment.

Foote drafted a cable TV ordinance after an outcry last year over poor service and sharp billing increases from many of Prince William's 26,000 cable subscribers. Supervisers were deluged with complaints about cable service last winter after Prestige, which serves about 15,000 households in the Dale City area, raised rates by about 80 percent, and some cable signals failed just before the Super Bowl.

The complaints have subsided since early this year, county officials and cable representatives said.

Supervisors and industry spokesmen agreed yesterday that the new ordinance is weaker than cable TV regulations currently in effect in neighboring jurisdictions. Most Northern Virginia jurisdictions effectively tax their cable firms' gross annual receipts, a cost that is then passed on to cable customers. Under Prince William's ordinance, cable subscribers will be charged an additional $1 annually, and that money will fund a cable regulator in the county's Office of Consumer Affairs.

Compton said the ordinance will drive up monthly charges to consumers because it requires a portion of the cost of some service extensions to be borne by cable firms.

He also said that a provision of the ordinance requiring refunds to customers who have lost cable service for more than 24 hours will be costly to administer and will increase subscriber prices. "There is some cost associated with the ordinance," said Foote. "But 10 percent -- that's not so."

Prestige's basic monthly charge to subscribers is now $9.95. Compton said he does not know when the rate will be increased.

"This ordinance is a reaction to those three or four months a year ago when there was erroneous billing," Compton said. "I think the supervisors have enacted an ordinance that will address the problems that the consumers had with the cable companies at the least cost.

Huge tracts of fast-growing Prince William County are not wired for cable, but all the cable firms operating now say they plan to expand their service. County officials have said they expect other cable companies to enter the market.