THE CORPORATE LIBRARY

Related Party Transactions and Outside Related Director Information

Western Alliance Bancorporation (WAL)

3/22/2006 Proxy Information

Ms. Johnson is the daughter of William S. Boyd and the sister of William R. Boyd, who are both directors and officers of Western Alliance. She also owns 20.01% of WAL shares.

The Company and the Banks have engaged in, and in the future expect to engage in, banking transactions in the ordinary course of business with directors, officers, and principal stockholders of the Company and the Banks (and their associates), including corporations, partnerships and other organizations in which such persons have an interest. These loans were made on substantially the same terms (including interest rates, collateral and repayment terms) as those prevailing at the time for comparable transactions with others and, in the opinion of management, do not involve more than the normal risk of collectibility or present other unfavorable features. At December 31, 2005, the Company’s officers, directors and principal stockholders (and their associates) were indebted to the Banks in the aggregate amount of approximately $27.6 million in connection with these loans. This amount was approximately 1.5% of total loans outstanding as of such date. All such loans are currently in good standing and are being paid in accordance with their terms.

SWVP Management Co. Inc. and the Company were parties to a Consulting Agreement dated as of January 1, 2003, pursuant to which consulting fees were paid to SWVP. Robert Sarver, the Company’s Chairman of the Board, President and Chief Executive Officer owns SWVP. The Company paid SWVP $60,000 in fiscal years 2003 and 2004. The agreement was terminated in 2005.

Todd Marshall, a director of the Company and BankWest of Nevada, is CEO Marshall Management Co. Marshall Management sub-leased office space from BankWest of Nevada during 2004 and 2005. The annual lease payments for 2005 totaled approximately $126,000. This sub-lease was terminated effective January 1, 2006. Todd Marshall is the son of director Arthur Marshall.

Certain Business Relationships

Robert Sarver, the Company’s President, Chairman and Chief Executive Officer, controls several limited partnerships which invest in commercial real estate. Directors Baker, Hilton, Mack, A. Marshall, T. Marshall and Richard Doan (director — Torrey Pines Bank), R. Luther Olson (director — Alliance Bank of Arizona), Thomas Rogers (director — Alliance Bank of Arizona) and Mark Schlossberg (director — Torrey Pines Bank) have invested in one or more of these partnerships as limited partners. None of these investments are related in any way to the Company’s operating or financial performance or the value of the Company’s shares. Mr. Sarver also is the managing partner of the entity which owns the Phoenix Suns NBA basketball team. Director Hilton and Francis Najafi (director — Alliance Bank of Arizona) are limited partners in the Phoenix Suns ownership group.

Mr. Sarver also serves as a director of Meritage Homes Corporation. Mr. Hilton is the co-chairman of the board and chief executive officer of Meritage. Other than Mr. Sarver, none of these directors is a managing or general partner in any of these entities, nor do they have any other role that would have a policy making function for such entities. William S. Boyd, a director of the Company, is the chief executive officer of Boyd Gaming Corporation. Marianne Boyd Johnson, Mr. Boyd’s daughter, is a director of the Company, BankWest of Nevada and Boyd Gaming Corporation. Robert L. Bougher, a director of BankWest of Nevada and Boyd Gaming Corporation, is the chief executive officer and president of the Borgata Hotel Casino & Spa, which is co-owned by Boyd Gaming Corporation. Donald Snyder, a director of the Company and BankWest of Nevada, was the president of Boyd Gaming Corporation from January 1997 until March 2005.