Regulations issued by the Board of Governors of the Federal Reserve System under this subchapter, in addition to regulating powers which a foreign branch may exercise under other provisions of law, may authorize such a foreign branch, subject to such conditions and requirements as such regulations may prescribe, to exercise such further powers as may be usual in connection with the transaction of the business of banking in the places where such foreign branch shall transact business. Such regulations shall not authorize a foreign branch to engage in the general business of producing, distributing, buying or selling goods, wares, or merchandise; nor, except to such limited extent as the Board may deem to be necessary with respect to securities issued by any “foreign state” as defined in section 632 of this title, shall such regulations authorize a foreign branch to engage or participate, directly or indirectly, in the business of underwriting, selling, or distributing securities.