ST. LOUIS (AP) — A former Missouri school superintendent who sharply increased the number of low-income and minority students in Advanced Placement classes is trying to do the same in three St. Louis-area schools.

Chris Belcher was troubled by the low number of low-income and minority students in AP classes in Columbia’s high schools, so in 2012 he worked with principals to change procedures for enrollment.

The St. Louis Post-Dispatch reports that 239 additional low-income and minority students enrolled in AP courses that year.

Belcher now is a superintendent-in-residence for the nonprofit organization Equal Opportunity Schools, which worked with him to address the disparities in Columbia.

The Parkway, Ferguson-Florissant and Belleville Township High School districts have agreed to a yearlong partnership with EOS to expand AP opportunities for their students.