CMS Energy will acquire a unit of Niagara Mohawk for more than $200 million.
The CMS Energy will take a $450 million charge against earnings because it might not recover costs on an unfinished nuclear plant.
CMS Energy is a member of the S&P 500 and the Fortune 1000.
CMS Energy fell $3.24, or 16.8 percent, to $16.05.
For example, CMS Energy, Michigan's largest natural gas utility, reported a $263 million loss this month.
CMS Energy said Hydra-Co will add significantly to profits next year.
It is a division of CMS Energy.
Yesterday, CMS Energy said that it had overstated its revenue by $3.4 billion, or 35 percent, last year as a result of sham electricity trades.
With its foreign ambitions, CMS Energy of Michigan is an aggressive company that growth investors might like.
CMS Energy has not estimated what such a conversion would cost.
