CAMP HILL, Pa. — A partner with a private equity firm that purchased preferred stock from Rite Aid in 1999 has joined the retail pharmacy chain’s board.

Rite Aid said Thursday that John Baumer, a partner with Leonard Green & Partners, had joined the board, replacing Jon Sokoloff, the firm’s managing partner, who has resigned from the board.

Leonard Green & Partners is an affiliate of Green Equity Investors III, which said it will re-elect Baumer for a one-year term at Rite Aid’s annual stockholder’s meeting on June 23.