The purposes of the corporate credit union are to:
(a) Accumulate and prudently manage the liquidity of its member credit unions through interlending and investment services;
(b) Act as an intermediary for credit union funds between members and other corporate credit unions;
(c) Obtain liquid funds from other credit union organizations, financial intermediaries and other sources;
(d) Foster and promote in cooperation with other state, regional and national corporate credit unions and credit union organizations or associations the economic security, growth and development of member credit unions;
(e) Provide payment systems and correspondent services to its members; and
(f) Perform such other services of benefit to its members which are authorized by the commissioner.