EXHIBIT 10.23



LOGO



AIR COMMERCIAL REAL ESTATE
ASSOCIATION

ASSIGNMENT AND ASSUMPTION OF SUBLEASE

AND CONSENT OF LESSOR/SUBLESSOR



|1. | ASSIGNMENT OF SUBLEASE
|-- | ----------------------



For valuable consideration, the receipt and adequacy of which are hereby acknowledged, Belvedere Trust Mortgage Corporation (ASSIGNOR)hereby assigns
and transfers to BT Management Holding Corporation (ASSIGNEE)all of ASSIGNORs right, title and interest in and to that certain SubLease dated January 6, 2005 (the Lease), by and between ASSIGNOR and Keefe,
Bruyette & Woods, Inc., as SubLessor, covering those certain Premises located at 235 Pine Street, Suite 1800, San Francisco, CA and as is more particularly described in such Lease.



This Assignment shall be effective: May 16, 2005.



In addition, ASSIGNOR hereby transfers to ASSIGNEE all of ASSIGNORs interest in and to any security or other deposits paid to SubLessor under the terms of such
Lease.



Assignee hereby grants to Assignor a nonexclusive license to enter the
Premises during the term of the Lease. No prior notice of entry is required for Assignor to exercise the rights granted under this paragraph.



|                     |  |  |  |                                                             |  |               |  |                         |  |         
|-------------------- |  |  |  | ----------------------------------------------------------- |  | ------------- |  | ----------------------- |  | --------
|Dated: May 16, 2005. |  |  |  | Belvedere Trust Mortgage Corporation,a Maryland corporation
|                     |  |  |  |                                                            
|                     |  |  |  |                                                             |  | By:           |  | /s/ Claus Lund         
|                     |  |  |  |                                                             |  | Name Printed: |  | Claus Lund             
|                     |  |  |  |                                                             |  | Title:        |  | Chief Executive Officer
|                     |  |  |  |                                                            
|                     |  |  |  |                                                             |  | By:           |  | /s/ Russell Thompson   
|                     |  |  |  |                                                             |  | Name Printed: |  | Russell Thompson       
|                     |  |  |  |                                                             |  | Title:        |  | Chief Financial Officer
|                     |  |  |  |                                                             |  |               |  |                         |  | Assignor



|2. | ASSUMPTION OF LEASE
|-- | -------------------



Assignee acknowledges that it has inspected the Premises and reviewed the Lease and Assignee hereby accepts the foregoing Assignment and assumes and agrees to be bound by and perform all obligations of the SubLessee
pursuant to the Lease arising on or after the date of this Assignment and to abide by all of the terms, provisions, covenants and conditions of the Lease.



|                    |  |  |  |                                                          |  |               |  |                         |  |         
|------------------- |  |  |  | -------------------------------------------------------- |  | ------------- |  | ----------------------- |  | --------
|Dated: May 16, 2005 |  |  |  | BT Management Holding Corporation,a Delaware corporation
|                    |  |  |  |                                                         
|                    |  |  |  |                                                          |  | By:           |  | /s/ Lloyd McAdams      
|                    |  |  |  |                                                          |  | Name Printed: |  | Lloyd McAdams          
|                    |  |  |  |                                                          |  | Title:        |  | Chief Executive Officer
|                    |  |  |  |                                                         
|                    |  |  |  |                                                          |  | By:           |  |                        
|                    |  |  |  |                                                          |  | Name Printed: |  |                        
|                    |  |  |  |                                                          |  | Title:        |  |                        
|                    |  |  |  |                                                          |  |               |  |                         |  | Assignee



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|3. | CONSENT TO ASSIGNMENT
|-- | ---------------------



Master Lessor and Sublessor hereby consents to the foregoing Assignment and Assumption of the Lease. It is understood and agreed, however, that the foregoing consent is
not a waiver of Master Lessors and Sublessors rights to consent to or impose restrictions upon any future assignment or subletting. In addition, this assignment does not release Assignor from liability for any of the obligations of the
SubLessee under the Lease.



|                     |  |                        |  |                               |  |               |  |                                                         |  |                      |  |              
|-------------------- |  | ---------------------- |  | ----------------------------- |  | ------------- |  | ------------------------------------------------------- |  | -------------------- |  | -------------
|Dated: June 13, 2005 |  |                        |  | Keefe, Bruyette & Woods, Inc.
|                     |  |                        |  |                               |  |               |  |                                                        
|                     |  |                        |  |                               | 
|                     |  |                        |  |                               |  |               |  | By:                                                     |  | /s/ ROBERT GIAMBRONE
|                     |  |                        |  |                               |  |               |  | Name Printed:                                           |  | Robert Giambrone    
|                     |  |                        |  |                               |  |               |  | Title:                                                  |  | EVP & CFO           
|                     |  |                        |  |                               |  |               |  |                                                         |  |                      |  | Sublessor    
|                     |  |                        |  |                              
|                     |  |                        |  |                               |  |               |  | Alecta pensionsforsakring, omsesidgt, a Swedish company
|                     |  |                        |  |                              
|By:                  |  | /s/ DANIEL J. GALLIGAR |  |                               |  | By:           |  | /s/ GREGG MEYER                                        
|Name Printed:        |  | Daniel J. Galligar     |  |                               |  | Name Printed: |  | Gregg Meyer                                            
|Title:               |  | Vice President         |  |                               |  | Title:        |  | Asset Mngr.                                            
|                     |  |                        |  |                               |  |               |  |                                                         |  |                      |  | Master Lessor



|    |  |                                                                        
|--- |  | -----------------------------------------------------------------------
|    | 
|By: |  | Alecta Investment Management, USA, Inc. A Delaware corporation, Manager



ATTENTION: NO REPRESENTATION OR
RECOMMENDATION IS MADE BY THE AIR COMMERCIAL INDUSTRIAL REAL ESTATE ASSOCIATION OR BY ANY REAL ESTATE BROKER AS TO THE LEGAL SUFFICIENCY, LEGAL EFFECT, OR TAX CONSEQUENCES OF THIS ASSIGNMENT OR THE TRANSACTION TO WHICH IT RELATES. THE PARTIES ARE
URGED TO:



1. SEEK ADVICE OF COUNSEL AS TO THE LEGAL AND TAX
CONSEQUENCES OF THIS ASSIGNMENT.



2. RETAIN APPROPRIATE CONSULTANTS TO
REVIEW AND INVESTIGATE THE CONDITION OF THE PREMISES. SAID INVESTIGATION SHOULD INCLUDE BUT NOT BE LIMITED TO: THE POSSIBLE PRESENCE OF HAZARDOUS SUBSTANCES, THE ZONING OF THE PROPERTY, THE STRUCTURAL INTEGRITY, THE CONDITION OF THE ROOF AND
OPERATING SYSTEMS, AND THE SUITABILITY OF THE PREMISES FOR ASSIGNEES INTENDED USE.



WARNING: IF THE SUBJECT PROPERTY IS LOCATED IN A STATE OTHER THAN CALIFORNIA, CERTAIN PROVISIONS OF THE ASSIGNMENT MAY NEED TO BE REVISED TO COMPLY WITH THE LAWS OF THE STATE IN WHICH THE PROPERTY IS LOCATED.



NOTICE: These forms are often modified to meet changing requirements of
law and industry needs. Always write or call to make sure you are utilizing the most current form: AIR Commercial Real Estate Association, 700 So. Flower St., Ste 600, Los Angeles, CA 90017. Telephone No. (213) 687-8777. Fax No.: (213) 687-8616.



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