COLUMBIA, Mo. (AP) -- Missouri offensive coordinator David Yost has resigned, effective immediately.

The university said Monday that Yost cited personal reasons for his resignation.

Yost has been an assistant under coach Gary Pinkel for 17 years, the last 12 at Missouri. He said in a statement that several factors led him to conclude it was the right time to move on.

Since coming to Missouri from Toledo with Pinkel in 2001, Yost has been the quarterbacks coach and recruiting coordinator until 2008. He was promoted to offensive coordinator in 2009 and was named assistant head coach in 2011.

Pinkel will conduct a national search for Yost's replacement but will also consider internal candidates. No timetable has been determined for finding a replacement.