Wis. Stat. § 221.0314
A bank may, by resolution of its board of directors authorizing such action, act as agent for the U.S. treasury or other instrumentality of the United States in connection with the sale of bonds or other obligations of the United States or an instrumentality of the United States, if designated as agent by the secretary of the U.S. treasury or by the other instrumentality. A bank may enter into contracts, incur obligations, make investments, pledge assets or take other actions if necessary or appropriate in order to act as agent under this section. A bank may exercise powers granted under this section only upon express approval previously granted by the division, and only in such manner and to such extent as the division may approve, and with such limitations upon the exercise of those powers as the division may impose.
Wis. Stat. § 221.0314