Mark G. Sheridan is a partner with diverse experience in many areas of litigation, with particular expertise in reinsurance and insurance coverage disputes. He has successfully argued matters in the Supreme Courts of Illinois and New Hampshire, as well as lower state and federal courts in California, Colorado, Delaware, Florida, New York, Pennsylvania, and Texas. Mark has received many professional awards, including having been named an Illinois Super Lawyer in the area of insurance coverage, and has been selected to the prestigious "Leading Lawyers" list published by the Law Bulletin Publishing Company.

Mark has arbitrated and litigated numerous reinsurance disputes under both treaties and facultative certificates, and he regularly advises ceding companies and reinsurers on their rights and obligations under a wide variety of reinsurance contracts. Mark has also successfully represented insurance companies in numerous complex insurance coverage disputes involving underlying claims of environmental property damage, construction defects, personal injury and advertising injury claims, and various toxic torts, including breast implants and asbestos.

Representative Matters

Westport Ins. Corp. v. California Casualty Management Co., Case 3:16-cv-01246 (N.D. Calif.  April 7, 2017)  Represented insurer seeking equitable contribution against excess insurer of the Association of California School Administrators arising from $15.8 million paid to settle three school molestation claims.  After addressing issues relating to lost policies, priority of “other insurance” provisions, and number of occurrences, the Court entered summary judgment and awarded equitable contribution of $2.6 million.

Pacific Employers Insurance Co. v. GLOBAL Reinsurance Corp. of America, 2010 WL 1659760 (E.D. Pa. April 23, 2010), reconsideration denied, 2010 WL 2376131, aff'd 693 F.3d 417 (3d Cir. 2012) 
Judgment on the pleadings for reinsurer; follow the fortunes doctrine did not require the reinsurer to pay expenses in addition to the limits of liability on the facultative certificates.

EnergyNorth Natural Gas Co. v. Certain Underwriters at Lloyd's, London, 934 A.2d 517 (N.H. 2007) 
In a matter of first impression, the New Hampshire Supreme Court unanimously adopted pro rata allocation for long-term environmental pollution claims.

Travelers Casualty & Surety Co. v. Gerling Global Reinsurance Corp. of America, 419 F.3d 181
(2d Cir. 2005)
 Cedent's post-settlement allocation of loss is controlled by the follow the fortunes doctrine.

Employers Insurance Co. of Wausau v. American Re-Insurance Co., 256 F. Supp. 923 (W.D. Wis. 2003) Cedent's declaratory judgment costs covered by facultative reinsurance certificates.

Guess, Inc. v. Zurich-American Insurance Co., No. 02C86420 (Cal. Super. 2001) 
Summary judgment granted for a general liability insurer, holding that the false imprisonment component of the "personal injury" coverage did not create a duty to defend a clothing manufacturer against claims brought by Vietnamese immigrants who alleged they were held in slave labor camps in central Los Angeles.

Travelers Casualty & Surety Co. v. Certain Underwriters at Lloyd's of London, 760 N.E.2d 319 (N.Y. 2001) Amicus brief for Reinsurance Association of America; court held that follow the fortunes doctrine does not apply to the interpretation of the reinsurance contract.

Hills v. Bridgeview Little League Association, 745 N.E.2d 1166 (Ill. 2000) 
In a matter of first impression involving the premises liability of a Little League baseball team, Illinois Supreme Court reversed judgment against the team.

Benoy Motor Sales, Inc. v. Universal Underwriters Ins. Co., 679 N.E.2d 414 (Ill. App. Ct. 1997) Costs incurred in responding to EPA administrative proceedings are insurable "damages" under general liability policies.

Bristol-Myers Squibb Co. v. AIU Insurance Co., 1995 WL 861100 (Tex. Dist. Ct. August 8, 1995) Summary judgment dismissing policies that expired prior to date on which insured acquired subsidiary that manufactured silicone breast implants.


ARIAS - U.S., Res Judicata and Collateral Estoppel in Arbitrations, New York (Nov. 2013)

Chicago Bar Association, Reinsurance Wars Revisited, Chicago (April 2009)

ARIAS – U.S., Intensive Arbitrator Training Workshop, Tarrytown, N.Y. (March 2008)

DRI Conference, Allocation Among Multiple Insurers and Reinsurance Explained, Chicago (October 2007)

DRI Conference, Hot Topics In Reinsurance, Chicago (May 2006)


"Environmental Coverage: Law and Litigation," Liability Insurance (IICLE 1996, 1998 Supp.)

"Coverage Issues Raised by E-Mail and the Internet," Commercial and Professional Liability Insurance (IICLE 2002)