Republican Ohio Treasurer Josh Mandel (man-DEHL') says he is dropping his U.S. Senate bid, citing his wife's health.

Mandel's decision announced Friday in an open letter to "friends and family" leaves Cleveland banker Mike Gibbons on the Republican side for now. Democratic Sen. Sherrod Brown is seeking a third term, after defeating Mandel in 2012.

Mandel says in his letter that his wife has a health issue that will require him being there for her and their three children. He calls the decision "difficult ... but it's the right one."

A message seeking comment was left Friday for Mandel.

The 40-year-old Iraq veteran says he will finish his second term as treasurer.

Brown unseated Republican Mike DeWine in 2006. DeWine is now Ohio's attorney general and is running for governor.