Marc J. Sonnenfeld


Noted by Chambers USA as “an established figure for both his commercial and securities litigation practices,” Marc J. Sonnenfeld defends class actions asserting violations of the federal securities laws, derivative cases, claims arising from mergers and acquisitions, and appraisal actions, as well as regulatory and enforcement proceedings. Marc has argued numerous successful motions to dismiss, including recent victories in the Sixth, Seventh, and Ninth Circuits, and been recognized for his extensive trial experience.


8/20/2018 - The Best Lawyers in America Names 18 Morgan Lewis Lawyers Practice-Specific ‘Lawyers of the Year,’ Recognizes Additional 203 Morgan Lewis Lawyers

5/21/2018 - Chancery Judge Denies Bid For Redo In HP-Aruba Appraisal, Law360

3/2/2018 - Morgan Lewis Advises ATA in Sale of ATA Online

2/15/2018 - Investors Sued for More in HP Deal, Got Less, The Deal

6/30/2017 - Brocade, Ruckus Shake Shareholder Suit Over $1.2B Deal, Law360

5/2/2017 - Morgan Lewis Partner Marc Sonnenfeld Receives Lifetime Achievement Award

1/19/2017 - 9th Circ. Won't Revive HP Investors' Suit Over CEO Ethics, Law360

9/14/2016 - Philly Soft Drink Tax Targeted In Beverage Groups' Suit, Law360

June 2016 - The Securities King of Pennsylvania, Super Lawyers

4/7/2016 - Morgan Lewis Partner Marc Sonnenfeld Inducted Into the International Academy of Trial Lawyers

11/20/2015 - Morgan Lewis Wins Class Action for Abeona Therapeutics

1/28/2015 - General Cable Ducks Suit Over Accounting Errors Theft

12/15/2014 - Chancery Halts Zimmer Investor Claims During Patent Appeal, Law360

6/26/2014 - HP Escapes Shareholder Suit Targeting Former CEO, Law360

5/23/2014 - Inquirer Ruling Casts Doubt on Pa. Power Over Delaware LLCs, Law360

2/4/2014 - Morgan Lewis Advises Chiesi on Completed Cornerstone Acquisition

10/16/2013 - BioClinica Investors Lose Bid To Block $123M PE Takeover, Law360

9/16/2013 - Morgan Lewis Advises Chiesi Farmaceutici on Merger Agreement with Cornerstone Therapeutics

8/12/2013 - Morgan Lewis Beats HP Securities Suit over Hurd Conduct, Am Law Daily

8/9/2013 - HP Escapes Shareholder Suit Targeting Former CEO, Law 360

7/3/2013 - Shipping Co. Danaos Wins Dismissal Of Shareholder Suit, Law360

3/6/2013 - Q&A With Morgan Lewis' Marc Sonnenfeld, Law360

2/20/2013 - GCs Name 24 Top White Collar, Securities Attys, Law360

1/7/2013 - Securities Group of the Year: Morgan Lewis, Law360

12/14/2012 - Securities MVP: Morgan Lewis' Marc Sonnenfeld, Law360

9/25/2012 - HP Beats Investor Claims Over Ex-CEO's Severance

9/12/2012 - Constar Directors Reach $23M Deal To Exit Investor Suit, Law360

9/5/2012 - Morgan Lewis Scores for Hewlett-Packard in Securities Case over webOS, Litigation Daily

9/4/2012 - HP Beats Securities Suit Over $1.3B Palm Acquisition, Law360

6/27/2012 - Chancery Court Dismisses Suit Over Former HP CEO's Severance Package, Delaware Business Court Insider

6/22/2012 - HP Investor Suit Over Hurd's $40M Payout Dismissed, Law360

5/21/2012 - 7th Circ. Rejects Securities Suit Over Zimmer Hip Implant, Law360

3/22/2012 - HP Boots Derivative Suit Over Alleged Bribes, Law360

11/29/2010 - Morgan Lewis Partner Receives 2010 Wells Fargo Fidelity Award

8/12/2010 - CardioNet Wins Dismissal Of Investor Class Action, Law360

View more...