The Iowa Public Employees' Retirement System, Des Moines, is keeping INVESCO Realty Advisors as manager of $225 million in a real estate separate account, said Michael L. Fitzgerald, state treasurer and a member of the $15.8 billion system's investment board. "Wilshire explained real estate is a totally separate operation," Mr. Fitzgerald said. "There is nothing affecting Iowa that was at risk or handled improperly. Performance has been good." Wilshire is the system's consultant.