Mass. Gen. Laws ch. 171, § 65E
A credit union shall have the following powers and any further incidental or complementary powers that may fairly be implied from those expressly conferred and such as are reasonably necessary to enable the credit union to exercise fully those powers according to common customs and usages:
(iii) to buy, sell or make loans as participation loans with any other federally-insured credit union, bank or insurance company and to service any loans sold by it.
This section shall be applicable to loans and mortgage loans authorized by sections 65A to 65E, inclusive.