Mich. Comp. Laws § 483.106: Common carriers; preference prohibited.

Sec. 6.

All corporations, associations and persons, purchasing or collecting natural gas and transmitting or conveying the same for hire, compensation or otherwise by pipe line or lines as a common carrier shall be a common carrier thereof as at common law, and it shall be unlawful for any such common carrier doing business within this state to give, either directly or indirectly, any preference or advantage to any person, copartnership, corporation or locality, in any respect whatsoever as to rates, service, facilities for service or commodity delivered.