Jeffrey B. Clay was unanimously recommended today as executive director of Pennsylvania Public School Employees' Retirement System, Harrisburg, by the $44 billion fund's personnel committee, said Evelyn Tatkovski, spokeswoman. The board of the $44 billion system will meet Oct. 31 to approve the appointment. Mr. Clay has been interim executive director since June, when Dale Everhart retired. Mr. Clay had been deputy executive director of the fund since January 1995. The next executive director will decide whether to fill that post, Ms. Tatkovski said.