Section 8. A trustee, a director or other officer of bank may at the same time be a director, trustee or other officer of a savings bank, co-operative bank or credit union, state or federally chartered savings and loan association, trust company or national banking association if, in such case, there is in force a permit therefor issued by the commissioner in writing with the reasons thereon stating why the public interest warrants its issuance, after reasonable notice and an opportunity to be heard, who may issue such permit if, in the commissioner's judgment, it is not incompatible with the public interest, and to revoke any such permit whenever the commissioner finds, after reasonable notice and opportunity to be heard, that the public interest warrants its revocation, except that this section shall not apply to any director or other officer who held such position at the incorporation of said trust company. Any person serving as a director, trustee or other officer of a bank that does not make real estate mortgage loans and does not accept savings deposits from natural persons, may at the same time serve as a director, corporator, trustee or other officer of a savings bank, co-operative bank, trust company, state or federally chartered savings and loan association, or national banking association.

Notwithstanding this section, a director, officer or employee of a bank may at the same time be a director, officer or employee of a banking institution if such bank and banking institution are affiliates of the same bank or mutual holding company. For the purposes of this section, the terms ''banking institution'' and ''affiliate'' shall have the same meanings as set forth in section 1 of chapter 167A.