After a decade of lobbying, promise making and plan changing, the executives and officials trying to bring a Major League Baseball team to Virginia believed they had one last chance.

Gov. Mark R. Warner had joined key lawmakers in balking at Virginia's plans for financing a new 42,500-seat stadium. But baseball negotiators, hungry for political certainty, had presented a radical idea: Could Virginia officials simply agree to give the hundreds of millions of dollars in tax revenue expected from the ballpark to baseball or team owners, who would then finance the ballpark themselves?

Members of the Virginia Baseball Stadium Authority rushed to secure assurances from Attorney General Jerry W. Kilgore that such handouts -- totaling about $1 billion over 30 years in one scenario -- were legal. Projections showed that once construction costs were covered, hundreds of millions of dollars in tax revenue could be left over for baseball or team owners to pocket, authority Chairman Keith Frederick said.

"They are taking more of the risk and getting more of the upside. That's business," Warner (D) said in an interview yesterday. "My responsibility was to guard the fiscal situation for the taxpayers."

The last-minute proposal, which emerged even as baseball officials were pushing ahead with negotiations with Washington officials about financing a stadium in the city, appears to have foundered, people involved with Virginia's bid said. Efforts continued to sweeten the deal by adding sources of revenue, but those, too, seem to have failed, those involved said.

Warner said the Montreal Expos appear headed to Washington, lured by a more generous financial package than Virginians could muster. He said the District's plan was $100 million better for baseball. "It's clear that the league is leaning towards the District," Warner said, adding that he thinks Northern Virginia "is still in the picture."

But what seemed to be the harried end to Virginia's long effort followed broader weaknesses and political missteps that plagued the state's bid and helped block a deal that Virginia insiders said was tantalizingly close.

"It's an error. This one bounced off the glove," said Rep. Thomas M. Davis III (R-Va.), a fervent fan who had discussions with baseball officials and was kept abreast of progress on bids from both Virginia and Washington.

"They wanted to put it in Virginia if they were able to. They weren't able to," Davis said, referring to baseball officials. "The District was able to give Major League Baseball the assurances they need, and Virginia was not. . . . The political leaders couldn't put it together, and in D.C. they did."

In the high-stakes, and highly secretive, process of bidding to host a team, "assurances" translate as dollars. Major League Baseball is exempt from antitrust laws, and owners can veto a move to a new home. In a twist, baseball's 29 team owners also own the Expos, giving them a direct financial stake in getting a high price for the franchise.

The District's $440 million plan to finance and build a ballpark using business taxes and stadium-related revenue is good for the sale price for two basic reasons: A team is worth more if it comes bundled with a new facility; and potential buyers can pay more for the Expos because they don't have to pay construction costs and are responsible only for annual rent payments.

Frederick argued that the late-blooming plan to channel Virginia's tax revenue to the baseball or team owners would be better for the Expos' owners and Major League Baseball in the long run.

"The District was offering a dedicated tax revenue source not tied to ballpark performance, which is the traditional way these deals are done," Frederick said, while Virginia was offering "all revenues pledged in the project. . . . In the end, the upside is much bigger."

A source close to the negotiations said a group separate from the Virginia authority talked with Major League Baseball officials as recently as last weekend to try to attract the team to Loudoun County. The offer fell short, and talks stalled, the source said.

Misjudgments and credibility issues have dogged Virginia's bid. In May, Gabe Paul Jr., the authority's executive director, assured baseball officials that Virginia's financing plan was solid.

"Virginia has a complete ballpark financing plan in law, on the books," Paul wrote. "We need no additional legislation to build Virginia's Ballpark under this plan."

In fact, authority officials needed the General Assembly to put the state's "moral obligation" on the line for stadium bonds, and they needed Warner to sign the legislation. Warner, along with Republican legislators, opposed putting the state's credibility behind the bonds.

The finger-pointing over who lost baseball has already begun.

"I certainly don't want to give D.C. any credit for the approach they took in getting the stadium. I don't think it's fair to the taxpayers," said Del. Richard H. Black (R-Loudoun). "But we're in a competitive situation with baseball, and if the governor is not willing to come to the table, we have no chance of winning."

Warner defended his efforts, noting that he was one of the original investors who launched Virginia's bid, and he said he did not let baseball slip through the state's fingers.

"I would categorically deny that," Warner said. "That's sour grapes from some disappointed baseball advocates."

Staff writer Chris L. Jenkins contributed to this report.