It was, the invitation said, a birthday party for Reston's cable television -- a system that in its 10 years of broadcasting has been down-home enough to produce a program for gardeners, spunky enough to interview a local prostitute and civic-minded enough to give nonstop coverage to meetings of the Reston Community Association.

But did the firm -- Warner Amex Cable Communications of Reston Inc. -- have anything in mind other than a birthday party for its Channel 8 station in Reston? The company sent invitations not only to a number of Reston residents, but to the entire Fairfax Board of Supervisors and other influential public figures in the county (along with some local journalists, including this one).

The question comes to mind because Warner Amex of Reston is part of Warner Amex Cable Communications Inc. (a jointly owned subsidiary of Warner Communications Inc. and the American Express Co.), which very likely, company officials say, will bid for the cable franchise covering all of Fairfax County. The competition for the franchise already is intense, and many potential bidders have hired so-called "rent-a-citizens" to make their proposals as attractive as possible.

Eight members of the Fairfax Board of Supervisors chose not to go to the party. Even Chairman John F. Herrity, who rarely misses a chance to mix with voters, said no thanks.

What they undoubtedly had on their minds when they sent their regrets was that less than 36 hours after the party, they would be making crucial decisions about the future of cable television in Fairfax. In the months ahead, there will be more decisions, culminating with the most important one of all: Which firm would win the countywide cable franchise and have a monopoly on one of the most affluent markets in the United States?

"It's a conflict of interest, without question," said Supervisor Joseph Alexander (D-Lee), explaining why he stayed away from the party.

"I assumed everyone would say no," said Supervisor James M. Scott (D-Providence).

The one supervisor who did not say no was Martha V. Pennino, who represents the Centreville District, where Reston is located.

"I don't know how it could be a conflict of interest," she said. "I socialized with people I socialize with daily -- my friends and constituents in Reston . . . This was a celebration for the community, and I am a member of the community."

Anyone who knows Pennino knows her cable TV votes are not going to be influenced by a party thrown by a potential bidder. It was Pennino, after all, who quickly criticized former supervisor Alan H. Magazine for becoming a stock-owning consultant to Storer Communications shortly after he left the board last December. Storer is a declared bidder for the Fairfax franchise.

Warner officials insist the party had nothing to do with any of its franchise-seeking intentions. Instead, they say, the party was strickly to recognize the hard-working men and women at Reston's Channel 8, who have produced an array of local programming that is admired (and sometimes copied) throughout the fledgling cable industry.

But it doesn't take a public relations expert to know that such an occasion -- intentionally or not -- can serve another purpose: To show county opinion makers (many of whom were at the party) that Warner Cable is a pretty nifty outfit, that What's good for Reston may be good for Fairfax.

Marcia E. McDevitt, the community programming coordinator for Channel 8, said she originally wanted a "small party. But somebody up there (at Warner, headquaters in New York) said, 'Hey, I didnt realize the Reston system was that old. We ought to do something special.' It grew like Topsy."

McDevitt said the supervisors were invited because they have all appeared on Channel 8 programs. The party was not held in July, the official birthday of Channel 8, because it "was too hot then," she said. Last Saturday was picked for the party, she added, because that was one of the few open slots at the Reston Community Center.

Coincidence, and nothing else McDevitt said, put the party just two days before supervisors were to make major decisions about cable TV.

Nonetheless, Channel 8's birthday party and Warner Cable's image-making got hopelessly tangled under the chandeliers of the Reston Center's community room last Saturday night.

McDevitt, for example, said in an interview later, "I'm going to do a little work for the franchise operation . . . We all want to get the countywide system."

Another celebrant, Mary Cahill, the respected and knowledgeable political commentator for Channel 8, is a paid part-time consultant for the Warner franchise operation.

Yet another celebrant was Christie Carpenter, coordinator for the franchise operation.

Each bag of goodies given to the 250 or so guests was chock full of handsomely printed material showing what a terrific company Warner Cable is. ("The Warner Amex people you will meet in the following pages exemplify the company's dedication to community service in every possible way to solidify an enduring relationship of community good will and public service," read one brochure.)

The hard-working people who created Channel 8 and who have kept it going with a mostly parsimonious budget deserved every minute of their birthday celebration.

They deserve, too, more recognition for their community programming.

They do not deserve to be used, however indirectly, to polish Warner Cable's image in the high-stakes franchise competition in Fairfax County.