EXHIBIT 21.1 SUBSIDIARIES OF THE REGISTRANT The following table shows all direct and indirect subsidiaries of the registrant except (1) subsidiaries which, considered in the aggregate as a single subsidiary, do not constitute a significant subsidiary, and (2) certain consolidated wholly-owned multiple subsidiaries carrying on the same line of business as to which certain summary information appears below. JURISDICTION OF INCORPORATION ----------------------------- Boston Gas Company Massachusetts Midland Enterprises Inc. Delaware 13 subsidiaries engaged in water transportation and related activities Water Products Group Incorporated Massachusetts WaterPro Supplies Corporation Massachusetts