To whom it may concern:

I am requesting to testify at the public hearings regarding proposed Regulation NMS (Securities Exchange Act Release No. 34-49325, File No. S7-10-04). I am flexible as to either of the April 1 or April 21 dates. A copy of my biography is provided for your convenience.

I will provide three copies summarizing my intended testimony on or before March 26 as requested. Should you have any questions in the interim, please feel free to contact me at the number below or e-mail me at

Regards - William O'Brien

William O'Brien
Chief Operating Officer
Brut, LLC
55 Broadway, 9th Floor
New York, NY 10006
Phone: (917) 637-2560
Fax: (917) 637-2597


William O'Brien is Chief Operating Officer of Brut, LLC. As COO, Mr. O'Brien participates in the management of all, strategic, operational and administrative affairs of the company. He also oversees planning for all company-wide projects and helps manage their execution. Mr. O'Brien originally joined Brut as Senior Vice President and General Counsel in September 2000, with responsibilities that included management of Brut's legal affairs, regulatory strategy and Compliance Department.

Previously, Mr. O'Brien was Vice President and Assistant General Counsel at Goldman, Sachs & Co., where he was responsible for providing legal and regulatory compliance coverage to the firm's prime brokerage, securities lending, equity financing and soft-dollar business units, as well as working on related custodial, clearance, settlement and operational issues. Before joining Goldman Sachs he was an Associate at Orrick, Herrington & Sutcliffe LLP, practicing in their Market Regulation Practice Group and working with a variety of broker-dealer clients, including the operators of electronic communication networks and other alternative trading systems.

Mr. O'Brien has co-authored several articles on various topics regarding broker-dealer regulation and equities market structure. He earned his undergraduate degree with honors from the University of Notre Dame and his law degree with honors from the University of Pennsylvania School of Law.