Joann E. Flaminio, executive director at the $6.4 billion Employees Retirement System of Rhode Island, Providence, is resigning effective June 30. She submitted her resignation at the pension boards March 8 meeting. Ms. Flaminio was hired as executive director in 1993 to help overhaul the pension system, which had been under criticism for pension abuse and mismanagement. She said she will take time off before taking another job. The fund is not yet searching for her replacement.