CHICAGO (AP) – Illinois Gov. Bruce Rauner has apologized for a 2011 email in which he characterized Chicago public school teachers as “virtually illiterate” and principals as “incompetent.”

The Republican governor told reporters Friday that the comments were “inaccurate,” “intemperate,” and he apologized to teachers. But he added that the pace of change in the nation’s third-largest school district was too slow.

His remarks – made before he was governor – were revealed Thursday in emails Chicago Mayor Rahm Emanuel’s administration released under a court order.

At the time, Rauner was a private equity executive and a large donor to the Chicago Public Education Fund, an education reform group.

He sought Friday to explain the remarks by saying he was passionate about the issue of education and frustrated at the pace of improvements.