Mich. Comp. Laws § 460.111: Definitions.

Sec. 1.

As used in this act:

(a) "Commission" means the public service commission.

(b) "Department" means the department of commerce.

(c) "Public utility" means a steam, heat, electric, power, gas, water, wastewater, telecommunications, telegraph, communications, pipeline, or gas producing company regulated by the commission, whether private, corporate, or cooperative, except a municipally owned utility.