The Lenfest Foundation today announced a $10 million challenge grant to expand the Teach for America program in Philadelphia over the next 10 years.

The program recruits top college graduates from across the country to be classroom instructors for at least two years in city schools.

The foundation said the grant is contingent upon Teach for America obtaining matching amounts from other private sources and sending at least 300 corps members to teach in Philadelphia's neediest public schools.

Teach for America, which is based in New York City, has been recruiting and training college graduates to teach in high-proverty urban and rural schools since 1990.

It has been sending instructors to help staff Philadelphia schools since 2003. This year there are 268 corps members teaching in Philadelphia schools.

The program is aimed at bringing talented college graduates to fill vacancies in schools in low-income areas that have a hard time attracting qualified teachers. During their two years with the program, corps members receive training from Teach for America and take additional course work.