A. Michael Pratt, the incoming chancellor of the Philadelphia Bar Association, will focus on repealing a tax he says has killed off growth among professional-services firms in the city and on pushing law firms to expand diversity initiatives.

In his inaugural address today, Pratt will lay out an aggressive agenda calling for the city's top firms to boost financial support for legal aid to the poor by 10 percent a year for three years.

Pratt also plans to announce that, as chancellor, he will appoint a full-time director of diversity at the bar association, who would assist local firms in recruiting minority candidates, advise them on how to retain minority lawyers, and keep statistics on diversity initiatives among Philadelphia law firms.

He is firmly in the camp of local lawyers who say there is an urgent need for Mayor-elect Michael Nutter and City Council to reduce and eventually eliminate the business-privilege tax, which effectively subjects professional-services firms to higher tax rates than what other businesses face.

Pratt, 48, said that while Philadelphia law firms had been prosperous in recent years, most of their growth has been outside the city, where tax rates were lower. He said a special bar association committee would make the economic case for repealing the tax to City Council.

"Studies have shown time and again that the city's tax structure is one of the principal reasons why businesses leave Philadelphia, do not expand here, or never locate here," Pratt said in a draft copy of the speech he plans to give today at a luncheon at the Park Hyatt Philadelphia at the Bellevue. "These studies are confirmed by our own experiences, as well as those of our clients."

When he takes office Jan. 1, Pratt will become the third African American to have been head of the city's bar association.

He is a partner at the Pepper Hamilton L.L.P. law firm, focusing on commercial litigation, but also had extensive experience in the corporate world working for a time as chief litigation counsel for corporate and toxic tort matters at Honeywell International Inc. He has also served as chief deputy solicitor for commercial litigation in the city law department.

Yet he is the product of humble circumstances.

Born in a tiny Western Pennsylvania town named Grindstone, he was the fourth of a dozen children, raised for a time by his mother alone. The house in Grindstone had no indoor plumbing, and the children shared beds.

He recalls a painful incident from his childhood, when his mother went to inquire about a house for rent, but was told by the landlord that he would not rent to blacks.

Pratt eventually went on to attend Washington and Jefferson College, where he did his undergraduate work, and then to Harvard Law School.

Pratt said city law firms were doing too little to help finance legal-aid programs for the poor, which are severely strained and having great difficulty keeping up with the demand for the services.

He said that law firm revenue in Philadelphia reached into the billions, but that the combined contribution of Philadelphia lawyers to legal-aid services was now only about $1.4 million a year.

He is proposing that city law firms increase their giving to legal-aid programs 10 percent a year for the next three years. Two firms - Montgomery, McCracken, Walker & Rhoads and Feldman, Shepherd, Wohlgelernter, Tanner & Weinstock - already have committed to that goal, he said. Pepper Hamilton will increase its giving 15 percent.

Just as important, Pratt said, is the need to boost diversity. He said that in conversations with other minority lawyers, many do not feel a part of the mainstream in their firms.

"The . . . recurring theme was frustration that the conversation about diversity is itself becoming disturbingly redundant," Pratt said in the speech draft. "In Philadelphia, lawyers of color continue to make up a small percentage of law firm attorneys and less than 3 percent of law firm partners."

Urging senior law firm members to reach out to young minority associates with challenging work opportunities, he said, is one way to bridge that gap.