Fumo's property-tax lawyer, Joseph C. Bright, said he was appealing the hike on Fumo's Victorian showplace at 22d and Green Streets because it was a "spot assessment," rather than part of the normal reassessment.

"The Pennsylvania law is clear. You cannot single out a property," said Bright, who regularly appeals assessment cases before the city's Board of Revision of Taxes.

Bright said he sent the appeal to the tax board about a week ago, but he declined to provide a copy. He said it was similar to appeals "that many homeowners file."

The next step is for the board to set a date for Fumo's appeal hearing, which is not expected until fall.

Fumo's home was one of 54 high-end properties reassessed in April after a public controversy about the senator's low property-tax assessment.

The Philadelphia Democrat is facing trial on a 139-count federal corruption indictment, and has been trying to raise money for his defense.

Last year, Fumo put his house up for sale for $7 million, even though it had the assessed value of only $250,000 for tax purposes. He later cut the asking price to $6 million. It's still for sale.

Now the tax board is assessing the property at just under $1 million, and Fumo's tax bill will go from $6,611 to $25,201 next year.

Bright said all the property owners reassessed along with Fumo were also unfairly hit with "spot assessments."

He said Fumo was not contesting the actual value that the tax bureau has placed on his home, but whether the reassessments were done fairly. For that reason, he contends, the increase was invalid.

Of the 54 properties, Fumo's home was hit with the biggest rate hike.

Other properties that were reassessed last month included the $3 million Center City home of the late novelist Pearl S. Buck and the $11 million Rittenhouse Square mansion of Henry S. McNeil Jr., heir to the Tylenol fortune.

Eugene Davey, the tax board's director of assessment, has insisted that Fumo was not subject to a spot assessment. He said the increase was part of the board's effort to revalue about 500 other large homes.

Davey, whose agency in past years has had a reputation for cronyism, said many high-end homes were underassessed because the board's computer system could not properly set values for those types of homes.

He said Fumo's home and the other 53 properties were selected because they all have more than 5,000 square feet of living space and are in or near Center City.

Kevin Feeley, spokesman for the board, said Fumo "is clearly entitled to file an appeal."

"His appeal will be treated like every other appeal," Feeley said.

He said another group of 50 to 75 deluxe properties - expected to focus on Chestnut Hill and Northeast Philadelphia - were slated for reassessment in a few weeks.

When the controversy over Fumo's low assessment exploded, Charlesretta Meade briefly resigned from her post as chairwoman of the tax board in protest over what she saw as the agency's reluctance to hike Fumo's taxes.

Some of the seven members of the tax board have been closely tied to Fumo. One board member, for example, has been Fumo's personal real estate agent.

The board eventually relented. Meade retained her post as chair, and it raised Fumo's assessment - as part of the group of 54.

Fumo has had luck with appeals in the past. In 2003, the board scaled back a plan to hike his property taxes.

But when reporters questioned that action, the board insisted that it had lost Fumo's file.