ST. PAUL — Minnesota Supreme Court Associate Justice Christopher Dietzen announced Thursday that he’s resigning at the end of August, giving Democratic Gov. Mark Dayton the opportunity to appoint a majority of justices on the seven-member court.

The 69-year-old associate justice said in an interview his decision to depart was a practical matter: He’ll hit the state’s mandatory retirement age of 70 in March. While he could have let voters pick his successor in the November election, he said he thought it better to leave it up to the governor and the state’s Commission on Judicial Selection, which helps find and recommend candidates.