Voters in the city of Manassas Park went to the polls yesterday to decide on an off-track betting measure in their community, but results were slow to come in, partly because of the time it took officials to count hundreds of absentee ballots.

If approved, the referendum would allow Virginia's horse racing industry to open its first betting parlor in Northern Virginia. Colonial Downs, the state's only parimutuel horse track, probably would operate the parlor.

Manassas Park Mayor F.C. "Frank" Jones Jr. said more than half of the city's 5,400 voters cast ballots yesterday, a turnout driven in part by the referendum on off-track betting, he said.

Colonial Downs has tried before to bring betting to Manassas Park. In 1996, voters defeated a similar, company-backed referendum by 74 votes. Since 1992, Northern Virginia ballot initiatives to allow off-track betting have been defeated soundly in at least four jurisdictions.

Again the track pinned its hopes on the city, wagering that most of Manassas Park's 5,400 registered voters would agree to bring the first legal betting parlor to Northern Virginia.

Colonial Downs officials, confident enough to lease space for a parlor in the city several weeks ago, argued that the difference between then and now is that the company has an established, successful record with six betting parlors across the state. The company projects that $90 million a year would be wagered at the Manassas Park parlor, providing $558,000 in tax revenue for the city annually and an important business opportunity.

Opponents included Rep. Frank R. Wolf (R-Va.), politicians from Prince William and Manassas, churches and the Prince William-Manassas Family Alliance.

Wolf, a longtime critic of gambling, has said that it leads to bankruptcy, crime and addiction.

"Whenever gambling comes, bad things come," he said. "That's why I've been opposed to it coming to Virginia."

James R. Socas, a Democrat who challenged Wolf in yesterday's election, said that he considered the referendum a matter solely for Manassas Park voters to decide and didn't take a position on it.

Worried that a betting parlor would add to traffic, promote behavior harmful to families and increase crime, Prince William supervisors officially opposed the measure. Manassas city leaders did the same, saying that such a facility could tarnish the area's family-friendly image.

Meanwhile, Manassas Park city leaders remained officially neutral, arguing that city voters should not be influenced by input from overzealous neighbors. As private citizens, however, several top officials signed a petition to put the item on the ballot. City Council member Noreen C. Slater petitioned a court to allow Manassas Park to hold the referendum.