The company providing cable television service in Fairfax County has asked the Federal Communications Commission to relieve it of more than $10 million in obligations it promised during contract negotiations three years ago.

In a petition to the FCC, Media General Cable of Fairfax Inc. argued that the costs of a range of services, including wiring of public schools and a commercial network information system, should be charged against the annual franchise fees it pays to the county because those services do not benefit all subscribers.

"The repercussions are not just here in Fairfax, but across the country," said Fairfax County Supervisor Thomas M. Davis III (R-Mason). "They are trying to make a fast buck by putting the buck ahead of their commitments."

"Our company in no way is trying to welch on any of the mandates that are part of the franchise," said Thomas E. Waldrop, executive officer and chairman of the board of Media General. "We don't think the law is presently clear. It's not an effort on our part to get from underneath our contract."

Media General said its petition is an effort to clarify "a very fuzzy kind of area" created by cable guidelines approved by Congress last October.

The guidelines limit the type of extra services jurisidictions can require cable companies to provide and, beginning in two years, bar local governments from regulating basic cable service.

Only a few cable companies have sought rulings from the FCC on the recent changes in the law, and the Fairfax case is the only one that deals exclusively with the relationship of extra services and franchise fees, according to Stephen R. Ross, chief of the FCC's cable television branch.

"The case has great national significance," said Cynthia M. Pols, an attorney for the National League of Cities, which has filed arguments with the commission strongly opposing the petition.

"Cable systems have the right to try to have their costs reduced to have less costs to pass on to the consumer," said Ed Dooley, spokesman for the National Cable Television Association, which represents the interests of cable companies.

Fairfax officials argue that Media General volunteered the $10 million in extra services it is now contesting.

"They're not keeping their word," said Supervisor Audrey Moore (D-Annandale). "It wasn't like somebody coerced Media General to make those offers . . . . Everything they offered was strictly volunteer."

FCC officials said they plan to rule on the petition next month as part of a broad-ranging interpretation of the new cable statutes.