WEALTHY businessman Tom Knox dropped another $3 million into his mayoral campaign over the last four months, pushing his total investment to $8 million of his own money as he continued to outspend all his rivals for the Democratic nomination.

Campaign finance reports filed yesterday with city election officials show that Knox wrote a $2 million check to his own campaign in January.

He added another $1 million last week to give his television advertising an extra boost, as several other Democratic candidates and a couple of independent political committees began to target Knox for criticism.

Total spending by the Knox campaign, going back to 2005, jumped to $8.2 million, nearly as much as his six Democratic opponents combined.

Among the other candidates, all coping with a city ordinance that puts limits on individual donations for the first time in city history, Congressman Bob Brady and former City Councilman Michael Nutter were the leading fundraisers.

Brady raised nearly $2 million in the first four months of the year, with heavy donations from union organizations, while Nutter raised nearly $1.7 million, with a broad base of more than 2,000 individual donors.

State Rep. Dwight Evans raised $1.4 million in the four-month period while Congressman Chaka Fattah raised nearly $1.3 million.

With two weeks left before the May 15 primary, all five of the major candidates listed six-figure campaign treasuries.

Knox still boasted the biggest balance, with $871,000 in the bank. Evans and Nutter were not far behind, each with cash on hand of around $540,000. Brady counted $386,000 on hand, while Fattah reported $210,000.

Meanwhile, one of the independent committees running ads against Knox thumbed its nose at city and state election officials by failing to identify the sources of $70,000 it spent on anti-Knox ads last weekend.

Washington, D.C., lawyer Donald R. Dinan, who filed papers with the IRS last month creating the Working People for Truth organization, sent word to the Daily News late yesterday that he had asked the city Board of Ethics for an "advisory opinion" on whether his group was required to file any reports.

But J. Shane Creamer Jr., interim executive director of the Board of Ethics, said he hadn't received the correspondence.

City and state election officials said Monday that because the Washington group was clearly raising and spending money to try to influence the Philadelphia mayor's race, it was required to follow Pennsylvania election laws and disclose how it was raising and spending money.

Among the candidates for City Council, the largest war chest appeared to be that of Council President Anna Verna, who posted a $383,000 balance for her race against former PHA attorney Damon K. Roberts.

That was after Verna made sizeable donations to eight of her Council colleagues - enough to get her re-elected as Council president if all eight hold onto their seats.

Verna gave $5,000 each to colleagues Marian Tasco, Joan Krajewski, Darrell Clarke, Daniel Savage, Frank DiCicco and Carol Ann Campbell. She gave $10,000 each to James Kenney and Bill Greenlee.

In the at-large race for City Council, Greenlee raised $107,000 and spent about $97,000, leaving him with approximately a $39,000 war chest, which included $28,000 raised last year.

At-large challenger Bill Green, an attorney and son of the former mayor, raised $257,000 and spent $74,000, leaving him $183,000 for the final days of the campaign.

Among his largest contributors were the electricians union Local 98 and the law firm of Pepper Hamilton, which both gave him $10,000.

At-large candidate Marc Stier raised almost $81,000 and spent $85,000 from January through April, leaving him almost $40,000 thanks to fundraising last year, but also $63,000 in debts.

And Andy Toy, another at-large challenger in his first bid for office, raised almost $85,000, spent $33,000, leaving him with $51,000.

In his campaign to unseat Councilwoman Carol Ann Campbell, whose campaign-expense report was not available late yesterday, attorney Matthew McClure raised more than $95,000 on top of $69,000 on hand. He's spent $85,000 and has about $80,000 left in the three-way battle, which also includes Curtis Jones Jr., whose report was not available.

In the sheriff's race, incumbent John Green had contributions of $88,000 and a balance of $43,000. One of his opponents, Michael Untermeyer, a developer and attorney, started the year with a balance of $149,000, raised $123,000 since January and has spent a whopping $202,000, including $33,000 for ads on KYW radio. *