The Board of Supervisors yesterday cleared the way for Cablevision of Loudoun to sell its franchise to Adelphia Communications Corp., the fifth-largest cable provider in the country.

The vote came after the cable companies agreed to a series of conditions set forth by the board, including a provision that Adelphia not raise the fee for basic cable service for at least two years.

Cablevision, which has about 30,000 subscribers in Loudoun, submitted requests for approval of the sale, as required by the Federal Communications Commission, to six towns and the county in May. The towns--Leesburg, Hamilton, Middleburg, Purcellville, Round Hill and Lovettsville--approved the sale after holding public hearings.

Most supervisors said they were happy with the agreement the county struck with Adelphia.

"We really didn't give up anything," said Supervisor David G. McWatters (R-Broad Run), chairman of the board's Internal Operations Committee, which negotiated the consent request with Adelphia.

The county hired several consultants and a lawyer, on a budget of $50,000, to help with negotiations and examine the financial health of Pennsylvania-based Adelphia.

The board rejected Adelphia's request for an extension of Cablevision's current franchise agreement, and as a result, it must be renegotiated in about six years.

Adelphia representatives said that, overall, they were happy with the agreement and with the chance to enter the Loudoun market.

"This will give us a very strong presence near the nation's capital," said Joseph Price, Virginia regional manager for Adelphia.

Consumers should not see any rise in rates directly related to the acquisition, Cablevision representatives said.

"I couldn't predict at this point what price changes there might be, but a change in price due strictly to the transfer [won't happen]," said Cablevision General Manager Noel Brown, who will remain in his position after the sale.

One of the main sticking points for supervisors had been $123,784 in outstanding franchise fees owed to the county by Cablevision's parent company, Benchmark Acquisition. In the initial negotiations, Benchmark had said it would raise money to pay the debt by charging a higher rate for new subscribers.

"My position was no way," McWatters said. The company has agreed not to pass on the cost to customers.

Meanwhile, Adelphia has agreed to upgrade 100 miles of cable in western Loudoun, which will mean more channels and better quality. Adelphia also has agreed to notify all customers of rate increases 60 days in advance instead of the 30 days' notice Cablevision now gives.

Another part of the agreement requires Adelphia to buy new equipment for Loudoun's public access stations, including video cameras, microphones and editing machines, and train those who use public access television.

In addition, the county has set a deadline of three years for providing cable access to six Loudoun public schools without service.

One controversial item left out of the agreement was open access, which would require Adelphia to open its high-speed lines in Loudoun to other Internet service providers to increase competition.

Open access has become a national debate between Internet service providers and cable operators. Cable operators argue that communities have no authority to impose such requirements, and the issue is being litigated across the country.

Earlier this month, the City of Fairfax made open access a condition for approving the sale of its cable provider, Media General Inc., to Atlanta-based Cox Communications Inc. Loudoun's agreement with Adelphia leaves room for an open access requirement in the future but does not make it a condition of the sale.

"There's no point in us insisting if it's not going to be won in court," McWatters said.

The vote approving the sale was 7 to 0, with one supervisor absent and Chairman Dale Polen Myers abstaining because of a controversy involving allegations by a former Cablevision employee that news coverage was biased in Myers's favor.