Amegy Bank Rated Excellent Nationally in Business Banking.

HOUSTON -- Amegy Bank today announced that it is a national and regional winner of the Greenwich Associates 2005 Excellence in Business Banking Award. The award is based on the results of Greenwich Associates' biennial survey which includes interviews with decision makers from more than 22,000 businesses with annual sales of $1 million to $10 million in 66 major markets.

At the national level, banks are recognized for excellent overall satisfaction, excellence for business bankers, branch service, call center service, online services and cash management quality. At the regional level, banks receive awards for excellent overall satisfaction and cash management. A total of 40 banks were recognized for Excellence in Business Banking.

"Keeping each customer satisfied is - and always will remain - our top priority, and we're thrilled with these results," said Paul B. Murphy, Jr., CEO. "Our staff is committed to providing stellar service and innovative products for businesses and individuals and we are gratified to see another example of how we are making a difference for our clients."

The award follows recent recognition from U.S. Banker magazine which named Amegy's Debbie Innes as one of its "25 Women to Watch."

For more information on this award and other Amegy Bank developments, please visit http://www.amegybank.com/press_release/index.aspx.

Greenwich Awards

The Greenwich Associates Excellence in Business Banking Awards are presented at national and regional levels. At the national level, banks are recognized in six categories; at a regional level banks receive awards in two categories. National categories include excellent overall satisfaction, excellence for business bankers, branch service, call center service, online services and cash management quality. At a regional level, banks receive awards for excellent overall satisfaction and cash management quality.

Amegy Bancorporation, Inc. (NASDAQ:ABNK), the parent company of Amegy Bank N.A., is the largest independent bank holding company headquartered in Houston, Texas. The Company focuses on commercial lending, treasury management and investment services for businesses, private financial management and trust services for families and individuals, and retail and mortgage banking services. The Company, with $7.89 billion in assets, has more than 75 full-service branches located throughout the Houston and Dallas metropolitan areas. The shareholders of the Company approved its merger with Zions Bancorporation on October 11, 2005. The closing of the transaction is expected to occur late in the fourth quarter of 2005, subject to regulatory approval and the satisfaction of customary closing conditions contained in the merger agreement.