Mo. Rev. Stat. § 274.230: Two or more associations may act jointly.

Any association may, upon resolution adopted by its board of directors, enter into all necessary and proper contracts, and arrangements with a corporation, person or other entity, for the more economical carrying on of its business or any part or parts thereof. Any two or more associations may, by agreement between them, unite in employing and using or may separately employ and use the same personnel, methods, means and agencies for carrying on and conducting their respective business.