Glancy Prongay & Murray LLP is investigating potential claims against the Board of Directors of OM Group, Inc. ("OM Group" or the "Company") (NYSE:OMG) related to the proposed acquisition of the Company by Apollo Global Management, LLC. (NYSE:APO). The transaction is valued at approximately $365 million. The Company's shareholders will receive $34.00 per share in cash for each share of OM Group they own. This investigation concerns whether the Board of Directors of OM Group breached their fiduciary duties to stockholders by failing to adequately shop the Company before agreeing to enter into the proposed transaction, and whether the Company has disclosed all material information to shareholders about the transaction. If you are a shareholder of OM Group, if you have information or would like to learn more about our investigation, or if you wish to discuss your rights or interests with respect to these matters, please contact Louis Boyarsky, Esquire, Glancy Prongay & Murray LLP, 1925 Century Park East, Suite 2100, Los Angeles, CA 90067, by telephone at (310) 201-9150 or Toll Free at (888) 773-9224 or by email to firstname.lastname@example.org. This press release may be considered Attorney Advertising in some jurisdictions under the applicable law and ethical rules.