Eastern Enterprises mainly operates through the subsidiaries, Boston Gas Company, Essex Gas Company, Midland Enterprises Inc and Colonial Gas Company. Boston Gas and Essex Gas are engaged in the transportation and sale of natural gas to residential, commercial and industrial customers. Midland Enterprises operates a fleet of barges and towboats on the Ohio and Mississippi rivers. Other subsidiaries of the company include ServiceEdge Partners, Inc. which offers heating, ventilation and air conditioning equipment and AMR Data Corporation, which offers customized metering equipment and services. During 1999, the company acquired Colonial Gas Company and entered into definitive agreement to be acquired by KeySpan Corporation and to acquire EnergyNorth Inc. Upto year ended 1999, the company has incurred $ 17.3 million towards year 2000 expenses. Natural gas distribution accounted for 71% of 1999 revenues; Marine transportation, 27% and other services, 2%.