initial public offering

EXHIBIT 10.27

June 23, 2005

Mr. Thomas Weisel
Thomas Weisel Partners Group LLC
One Montgomery Tower
120 Kearney Street, 37th Floor
San Francisco, CA 94104

Dear Thom:

     The purpose of this letter is to set forth certain understandings between Thomas Weisel Partners Group LLC (“TWP”) and California Public Employees’ Retirement Fund (“CalPERS”) with respect to TWP’s proposed initial public offering (the “IPO”) and the restructuring of CalPERS’ securities that will be required for the IPO to proceed. The restructuring contemplated by TWP would include the conversion of all shares of TWP into shares of common stock of a new corporate entity. TWP desires to obtain certain commitments from CalPERS and other members of TWP for the purpose of facilitating its efforts to complete the restructuring and move forward with the proposed IPO. To allow discussions and negotiations on the restructuring to take place, TWP and CalPERS are willing to enter into this letter agreement.

     All capitalized terms used but not otherwise defined herein have the meanings set forth in TWP’s Amended and Restated Limited Liability Agreement dated November 21, 2001 (the “LLC Agreement”).

     1.  Limited Suspension of Put Rights . The parties acknowledge that CalPERS is currently entitled to certain rights to require TWP to redeem CalPERS’ Class D Redeemable Convertible Shares under subsections (a) and (c) of Section 11.4 of the LLC Agreement (the “Put Rights”). Subject to the terms and conditions set forth herein, CalPERS agrees not to exercise its Put Rights for a period commencing on the date this letter is executed by TWP (the “Effective Date”) and ending on the Suspension Expiration Date, defined as the earliest to occur of: (i) August 31, 2005, (ii) the receipt or delivery by