No one had ever donated anywhere close to this much cash for a political campaign in Pennsylvania.

Previous reports showed that a trio of executives at Susquehanna International Group in Bala Cynwyd already had ventured far into historic territory by giving at least $3 million to support State Sen. Anthony Hardy Williams' Democratic primary race for governor.

Postprimary reports are now in, and they reveal that the number was actually higher. A lot higher: $5,385,000.

Joel Greenberg gave $2.07 million. Jeffrey Yass contributed $1.86 million. Arthur Dantchik chipped in $1.45 million.

Not counting a few cases in which a wealthy candidate has financed his own campaign - Philadelphia mayoral contender Tom Knox spent $11 million on his primary in 2007 - these sums far exceeded all Pennsylvania benchmarks, veteran analysts said.

Not even Gov. Rendell, the most prolific fund-raiser in state history, ever had million-dollar donors.

"Ed never got close to a million dollars from anyone," said Comcast Corp. executive David L. Cohen, Rendell's closest political ally.

"I have never seen anything like this; it's just stunning," said Alan Kessler, a Philadelphia lawyer, who has specialized in Democratic fund-raising for two decades.

"It is amazing, absolutely astounding," said Barry Kauffman, executive director of Common Cause in Harrisburg, which is fighting to have Pennsylvania join 39 states that impose limits on donations to campaigns. New Jersey, for instance, caps gubernatorial donations at $3,400; Delaware caps them at $1,200.

The Pennsylvania Department of State said Tuesday that Williams, of West Philadelphia, had yet to submit his final campaign finance report, which by law was due Thursday.

But another report, submitted by the political action committee through which the Susquehanna executives mostly funneled their money to Williams, showed that the three donated $2.9 million to the Williams effort in the final eight days before the May 18 primary.

The bulk of that money went into TV and radio advertising, as Williams sought to catch up to poll-leader Dan Onorato, the Allegheny County executive.

In the end, Williams finished third, behind both Onorato and state Auditor General Jack Wagner.

The three executives had said through a spokesman before the primary that they were backing Williams because they liked his stance on school choice, particularly the use of publicly funded vouchers to enable more families to pay for private education.

Greenberg, on Monday, politely declined to talk to a reporter. Yass and Dantchik did not respond to requests for comment left at their offices.

The three men are founders of Susquehanna, a highly successful trading firm that bills itself as one of the largest privately held financial institutions in the world.

Students First, the PAC that transferred most of the executives' money into the Williams campaign, was financed almost entirely by Greenberg, Yass, and Dantchik.

The PAC's final campaign finance report for the primary period showed that it had only three other donors. Former Democratic State Sen. Connie Williams, of the Philadelphia suburbs, donated $5,000 to the PAC. Jackson Collins, listed as admissions officer of Episcopal Academy, contributed $2,000. Laura Beacham Byers, of Philadelphia, gave $1,000.

Williams, by not filing his report on time, subjected his campaign to a possible fine. But under state campaign laws, the maximum penalty is small: $250.

Even some fund-raisers think the time has come for limits on cash donations in Pennsylvania - if limits on self-financing by rich candidates are also instituted.

Speaking of the Williams backers, veteran Democratic fund-raiser Kenneth Jarin, a Philadelphia lawyer, commented: "These donors were certainly within their legal rights. But, yes, there should be some reasonable limits."

Contact staff writer Tom Infield

at 610-313-8205 or tinfield@phillynews.com.