A former longtime senior aide and family friend to New York Gov. Andrew Cuomo, Joseph Percoco, was convicted of bribery and fraud Tuesday in a federal corruption case for conducting a pair of schemes to sell his public office for personal profit.

Mr. Percoco was found guilty by a 12-person federal jury in Manhattan of three counts, including two counts of conspiracy to commit fraud and one count of bribery, capping an eight-week trial that laid bare the inner workings of the Cuomo administration and the backroom dealings of...