Businesswoman Rosemarie Greco and Philadelphia School Reform Commissioner Sandra Dungee-Glenn were named yesterday to head a task force that will find new strategies for recruiting and keeping high-quality teachers in city classrooms.

Paul G. Vallas, district chief executive, made the announcement at a reception for the 598 new teachers hired by the district this school year.

Vallas said last night that he also wants to help new teachers pay for the courses they need to meet state requirements for their continued certification.

Even with the new hires, Philadelphia still has 91 teaching vacancies. That leaves about 2,700 district students still without permanent teachers.

Among this year's new hires, fewer than half have full certification. The district's human-resources director, Marjorie Adler, said that 248 of the hires are fully certified, meaning they completed required courses in education and passed state certification tests.

Among the rest, 157 have yet to take or pass all four state tests; 125 are apprentices who lack education coursework; and 68 have not completed all their Philadelphia interviews and paperwork.

Adler said only six of the new hires have permanent state certification, which requires teaching for three years or more.

"We're not attracting any experienced teachers from other districts," she said.

Attracting highly qualified teachers has been one of Philadelphia's biggest problems as it seeks to improve academic achievement in its schools. Recent studies have shown that good teaching is more important than a student's socioeconomic background in raising test scores.

Contributing to the problem are Philadelphia's teacher salaries, which lag behind those in most surrounding suburbs, and more difficult working conditions in city classrooms.

Most of the new Philadelphia teachers are assigned to schools in the southwest, west, east-central and northern parts of the city, the areas with the neediest students. Relatively few are teaching in schools in the Northeast, which are popular with experienced teachers.

As for the vacancies, 49 of them are in the 45 schools being run by outside managers. Among the vacancies are 11 vocal-music teachers in the 20 schools run by Edison, which emphasizes art and music instruction.

District spokeswoman Barbara Farley said the newly appointed task force would "incorporate successful recruitment practices from other institutions, large and small businesses, nonprofits, and the military."

The group will be part of a new district initiative called the Campaign for Human Capital.