RALEIGH, N.C. -- North Carolina's state treasurer has unveiled rules banning employees from taking gifts from companies that do substantial business with the agency.

Treasurer Janet Cowell also announced Friday her top-level staff can't solicit charitable donations of more than $150 from contractors doing more than $10,000 worth of business a year with her office.

The rules come after former chief investment officer Patricia Gerrick said she was offered favors from investment firms but didn't accept them. Gerrick also said investment managers made donations to a charity on which she was a board member.

Cowell fired Gerrick in September after five years managing North Carolina's pension funds, which are valued at more than $60 billion. Cowell won't say why Gerrick was let go.

(This version CORRECTS the month of termination as September instead of August.)