Exhibit 99.1

                Willis Appoints Anna Cheng Catalano to Its Board

    NEW YORK--(BUSINESS WIRE)--July 21, 2006--Willis Group Holdings
Limited (NYSE: WSH), the global insurance broker, today announces the
appointment of Anna Cheng Catalano, a recognized figure in the global
petroleum industry, to its Board of Directors.
    During a career spanning over 20 years with Amoco Corporation and
subsequently BP plc, Ms. Catalano held a variety of U.S. and global
positions including sales operations, technical R&D, strategic
planning, marketing, international business development, and general
management. She held the top marketing position at BP, responsible for
repositioning the company's approach in its market facing businesses
from being product-driven to customer-led. After the launch of BP's
brand in 2000, Anna was responsible for the stewardship as well as
being a key driver of the "Beyond Petroleum" program.
    As President of Amoco Orient Oil Company in the mid 1990s, Anna
established and managed Amoco's first downstream refining, marketing
and transportation business in the People's Republic of China. She
opened Amoco's first office in Beijing, creating a team of expatriate
and national employees to identify opportunities for building a
presence in the country. In 1998 she was Senior Vice President, Sales
Operations for Amoco, responsible for Amoco's retail network across
the U.S. and in 1999 she was named BP's Group Vice President, Emerging
Markets, with responsibilities for Asia, Africa, Latin America,
Eastern Europe and the Middle East.
    "With her unique advantage of cultural fluency coupled with a
strong sense of business practices, Anna Catalano brings excellent
business instincts and a global, multi-cultural perspective to
Willis," said Joe Plumeri, Willis Chairman and CEO. "I am very excited
that she has accepted our invitation to join our team of Board members
whose combined global business understanding will help propel the
Company to the next level and beyond."
    The addition of Catalano to the Willis Board brings the total to
13, twelve of whom are independent.
    Ms. Catalano holds a B.S. degree in Business Administration from
the University of Illinois, Champaign-Urbana. In addition to
frequently speaking on strategic marketing and global branding, Anna
is a forthright leader on the mentoring and the advancement of women
in business and in recognition of her efforts she was recognized by
Fortune Magazine in 2001 as being among "The Most Powerful Women in
International Business". Anna currently serves on the Boards of
Directors of SSL International, plc., and Hercules Incorporated. She
is also a member of the Board of Directors of the Gulf Coast Juvenile
Diabetes Research Foundation.

    Willis Group Holdings Limited is a leading global insurance
broker, developing and delivering professional insurance, reinsurance,
risk management, financial and human resource consulting and actuarial
services to corporations, public entities and institutions around the
world. With over 300 offices in more than 100 countries, its global
team of 15,400 Employees and Associates serves clients in some 190
countries. Willis is publicly traded on the New York Stock Exchange
(NYSE: WSH). Additional information on Willis may be found on its web
site: www.willis.com.

    CONTACT: Willis Group Holdings Limited
             Investors:
             Kerry K. Calaiaro, +1 212-837-0880
             kerry.calaiaro@willis.com
             or
             Media:
             Dan Prince, +1 212-837-0806
             daniel.prince@willis.com