53 Pa. Stat. § 5505
The city shall invest the moneys of any charitable use or trust or of the estate of any minor of which it may be guardian in such common trust fund by adding the same thereto and by apportioning a participation therein to such use or trust or the estate of any minor of which it may be guardian in the proportion that the moneys of the use, trust or estate added thereto bears to the aggregate value of all the assets of such common trust fund at the time of such investment, including in such assets the moneys of the use, trust or estate so added. The withdrawal of a participation from such common trust fund shall be on a basis of its proportionate interest in the aggregate value of all the assets of such common trust fund at the time of such withdrawal. The participating interest of any use, trust or estate in such common trust funds may from time to time be withdrawn in whole or in part by the city. Upon such withdrawals the city may make distribution in cash or ratably in kind, or partly in cash and partly in kind. Participations in such common trust funds shall not be sold to any other corporation or person, except a nonprofit corporation organized and existing for a public charitable purpose.
53 P.S. § 5505