Exhibit 99.1 ------------ Joint Filing AgreementJoint Filing Agreement • December 29th, 2008 • Midamerican Energy Holdings Co /New/ • Electric, gas & sanitary services
The undersigned hereby agree that the statement on Schedule 13D with respect to the Common Stock of Constellation Energy Group, Inc., is, and any amendment thereto signed by each of the undersigned shall be, filed on behalf of each undersigned pursuant to and in accordance with the provisions of 13d-1(k) under the Securities Exchange Act of 1934, as amended.
OFAssignment and Assumption of Rights • December 29th, 2008 • Midamerican Energy Holdings Co /New/ • Electric, gas & sanitary services • New York
