John Harmon, the corporate secretary and senior vice president of Ankeny, Iowa-based Casey’s General Stores, entered a severance agreement dated Jan. 17, according to documents filed with the Securities and Exchange Commission. Harmon has been with the company since 1976 and was named secretary/treasurer in 1998.

Company spokesman Bill Walljasper said Harmon’s decision to leave was somewhat unexpected, but that Harmon decided to retire early.

Harmon’s duties included overseeing mergers and acquisitions, a critical area for the company, which has been in an expansion mode in recent years, acquiring other convenience store chains. The most recent acquisition included 33 HandiMart stores from Nordstrom Oil Co. of Cedar Rapids last year. The company said in December it plans to acquire another 50 stores and build 10 others by April 30. Currently, Casey’s operates 1,450 convenience stores in nine Midwestern states.

As part of the separation agreement, Harmon, who agreed to assist the company in the transition as his duties are reassigned, will collect his salary until April 30. Documents indicated his base pay was about $300,000 last year. He’ll also get about 71% of any bonus that would have been awarded on June 30 and he’ll be paid for 11 days of unused vacation.

Beginning May 1 and continuing for 20 years, Harmon will receive $71,250 a year. He’ll also receive group health insurance coverage for himself and his wife for 20 years or until Medicare coverage becomes available.