MUNCIE, Ind. – Ronny Thompson has told Ball State he will resign after one season as head coach. Thompson led the Cardinals to a 9-22 record last season and the school has said he and his staff broke NCAA rules by being at voluntary offseason team workouts.

Thompson sent a letter to the university Thursday indicating his plans to resign, school officials said.

“Its disappointing,” athletic director Tom Collins said. “We worked very hard with Ronny. I wanted this to work.”

Ball State planned a news conference Friday to discuss Thompson’s resignation.

University spokesman Tony Proudfoot said the search for a new coach would begin immediately. He said several factors contributed to Thompson’s decision to resign.

“Coach Thompson has expressed concern about the recent NCAA investigation as well as other issues,” Proudfoot said.

The Associated Press left a phone message seeking comment from Thompson.

Ball State has said Thompson, who was named coach in April 2006, and his staff broke the NCAA rules last summer and in May by being at voluntary offseason team workouts. The school said the coaches lied about their involvement in the May violations.

Last month, notes including racial slurs and insults were slipped under the office doors of Thompson and other staff members. The university was investigating the source of the notes.

Thompson is a son of Hall of Fame coach John Thompson, who won a national championship in his 27 seasons at Georgetown. His brother, John III, led Georgetown to the Final Four last season.

A service of the Associated Press(AP)