DOVER, Del. — State officials may have to run through the NCAA and National Football League before they can score additional revenue for Delaware through a sports betting lottery.

Representatives of the NFL and National Collegiate Athletic Association visited Dover this week to lobby against Gov. Jack Markell's proposal to reauthorize sports gambling in Delaware.

NCAA officials are threatening to ban all playoff games in Delaware if the state legalizes sports betting, and NFL representatives made their opposition known in a brief meeting with Markell on Thursday.

"I welcomed them to Delaware and they told me that they hoped I would reconsider my position," Markell said. "I told them I think we're coming from different places."

Markell is defending the proposal as a way to bring much-needed revenue into the state's general fund.

The proposed sports betting lottery is expected to generate about $55 million for the cash-strapped state in its first year if it clears the General Assembly.

By virtue of a brief and unsuccessful experiment with a sports lottery in the late 1970s, Delaware is one of only four states, along with Nevada, Montana and Oregon, grandfathered under a 1992 federal law that bans sports gambling.

Delaware's status as the only state east of the Mississippi River that can offer sports betting could provide an economic buffer against slot machine competition in neighboring Pennsylvania and Maryland.

The NFL, which has several teams in neighboring states, has long opposed sports betting, saying it would tarnish the game's image and could lure youngsters into gambling, though the lottery would be restricted to people 21 and over.

And NCAA officials said a sports betting lottery would make Delaware off-limits for any postseason championship events. NCAA spokeswoman Stacey Osburn said NCAA policy prohibits the staging of any session of an NCAA championship in any metropolitan area where legal sports wagering is allowed.

The potential effect of the policy on Delaware is unclear. NCAA playoff games there have been limited in recent years to University of Delaware football games, the last being a 2007 matchup with Delaware State University. The University of Delaware, a Division I-AA school, also hosted the Division I men's lacrosse championships in 1984 and 1986, and first-round lacrosse contests in 2002.

State officials note that the sports betting proposal would prohibit betting on Delaware teams. They argue that the NCAA's position seems inconsistent and point to the annual Las Vegas Bowl football game, and skiing championship events that have been held in Nevada.

"I don't know if it's retaliatory or just a bluff, but it strikes me as a little overreaching on their part," said Markell's chief of staff, Tom McGonigle.

McGonigle said the state has not ruled out a challenge to the NCAA policy.

Osburn, the NCAA spokeswoman, said there has been no inconsistency. She said the Las Vegas Bowl is not an NCAA event, and a skiing event held in Nevada in 2004 took place before the anti-sports wagering policy had been extended from men's basketball to all NCAA sports.

Osburn said the decision to use Reno, Nev., as a site for this year's West Regional skiing championships was "an administrative oversight on our part."