Arch Capital Group Ltd.

Waterloo House, Ground Floor

100 Pitts Bay Road

Pembroke HM 08

Bermuda

March 1, 2017

U.S. Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Re: Notice of Disclosure Filed in Exchange Act Annual Report Under Section 219 of the Iran Threat Reduction and Syria Human Rights Act of 2012 and Section 13(r) of the Exchange Act

Ladies and Gentlemen:

Pursuant to Section 219 of the Iran Threat Reduction and Syria Human Rights Act of 2012 and Section 13(r) of the Securities Exchange Act of 1934, as amended, notice is hereby provided that Arch Capital Group Ltd. has made disclosure pursuant to such provisions in its Annual Report on Form 10-K for the fiscal year ended December 31, 2016, which was filed with the U.S. Securities and Exchange Commission on March 1, 2017. Such disclosure appears on page 200 of the Annual Report on Form 10-K and is incorporated by reference herein.

Sincerely,

/s/ Mark D. Lyons

Mark D. Lyons

Executive Vice President, Chief Financial Officer and Treasurer