Beckman Coulter Inc., which makes medical testing instruments, said Tuesday that Scott Garrett has resigned as chairman, CEO and president.

The board of directors appointed J. Robert Hurley as interim president and CEO. Hurley has served as the company's senior vice president of human resources and chairman of Beckman Coulter Japan since 2005.

Glenn S. Schafer, lead independent director, was appointed by the board as non-executive chairman.

Garrett, 60, will remain as a full-time, non-executive employee of the company through Jan. 15.

Garrett has been CEO for the past five years, and said in a statement released by the company that he felt the company "is positioned to achieve its long term potential."

Neither Garrett nor the company said in the release why he was leaving, however.

In the statement, Shafer said the board "appreciates Scott's contributions to the company's success" and is "confident in and supportive of the company's management team."

The resignation comes months after the company's March announcement that it would need to regain approval for its AccuTnI troponin test kits, which are used to determine if a patient has suffered a heart attack.

In July, Beckman Coulter reported a 27 percent drop in second-quarter net income while cutting its full-year outlook.