PITTSBURGH — XTO Energy, a subsidiary of ExxonMobil with drilling operations in Butler County, has donated $26 million to the national College Readiness Program to expand opportunities in Western Pennsylvania schools.

The grant, which was announced at a news conference last week, goes to the National Math and Science Initiative, which runs the three-year College Readiness Program, designed to increase student participation in Advanced Placement courses, according to program manager Jaclyn Castma.

“We believe that AP courses are the way to improve college readiness,” Castma said. “If the student’s plan is college, we recommend that they take at least one AP course so they can see the rigor of a college-level class in high school. The work that these students are doing in the 10 months in the AP class is really what’s going to pay off in making sure that they’re ready for college.”

The program includes extensive teacher training as well as student-level and school-level support, Castma said.

The expansion of the program, possible through XTO’s grant, will happen over the next three years, including an estimated 40 new schools.

“Based on the generous contribution, we’re able to continue to bring on a large number of schools beginning in 2017-2018,” Castma said.

Schools in Butler County have been made aware of the program, for which they must apply to participate.

“We have a lot of opportunities for schools to come in starting in 2017 and beyond, and we’re really hoping to expand our presence into Butler County,” she said.

Schools in the county have shown interest in applying, but Castma said nothing has been formalized.

Amy Dobkin, community relations manager for XTO Energy, said the company hopes the investment will help improve the region and strengthen education.

“As they were looking to expand into other regions or even increase expansion, Pennsylvania was a focus for ExxonMobil and XTO Energy,” Dobkin said. “One of the core pillars of community outreach is partnering with education, to create opportunities and enhance the offerings to give students the tools to excel ... anything we can do to further enhance a child’s opportunity in education and overall better work force opportunity for our company and for others.”

ExxonMobil has been a partner with the National Math and Science Initiative for about a decade, Dobkin said.

The initiative’s website says ExxonMobil has provided more than $50 million over the years, according to the 2014 annual report available at www.nms.org.

The College Readiness Program has been in more than 1,000 schools in 34 states and also helps increase college readiness and AP participation for female and minority students.