EEP Enbridge Energy, L.P. Class A Common Units (delisted)

Enbridge Energy Partners LLP (EEP) is investigating the cause of a pipeline leak in eastern Michigan, according to a government filing made pubic Thursday.

Enbridge Energy is owner of the pipeline that spilled 20,000 barrels of oil in Michigan's Kalamazoo River in July 2010. Enbridge Energy said it discovered a small amount of oil Thursday in the soil near the town of Sterling in Arena county, according to the company's filing with the National Response Center. The amount of oil was not given.

An Enbridge spokeswoman was not immediately available.

-By Ben Lefebvre, Dow Jones Newswires; 713-547-9201; ben.lefebvre@dowjones.com