Arcadis NV — Earnings Release 2011

Oct 17, 2011

ARCADIS NV Gustav Mahlerplein 97-103 P.O. Box 7895 1008 AB Amsterdam The Netherlands Tel +31 20 2011 011 www.arcadis.com

PRESS RELEASE

ARCADIS PROVIDES TRADING UPDATE RELATED TO MERGER WITH EC HARRIS

October 17, 2011 – ARCADIS (EURONEXT: ARCAD), the international design, consulting, engineering and management services company, today provided a trading update based on the preliminary 2011 third quarter results. This trading update is related to the announcement today of the plan to merge with EC Harris LLP, an international built asset consultancy headquartered in London, U.K., providing high-value consulting and management services for the realization and operation of buildings, manufacturing and processing plants and infrastructure facilities. Reference is made to the separate press release issued today to announce this merger.

The preliminary third quarter results indicate the following:

• − Developments generally in line with those in the first half of 2011.
• − Revenues down by 2-3%, mainly due to negative currency impact of 5%. Organically, revenues continue growth at 3%.
• − Favorable market conditions in South America continue, driven by investments in mining and energy, resulting in strong growth in Brazil and Chile.
• − The United States environmental business continues organic growth at good levels, while project and program management activities also increase, partly offset by negative growth in water, due to pressure on local government budgets.
• − RTKL continues to expand in Asia and the Middle East.
• − In Europe, Germany and France develop well, while activities in the U.K. are picking up, especially thanks to private sector spending. Lower government demand results in reduced activities in the Netherlands and Belgium. In Poland revenues decline sharply as major road projects were put on hold.
• − Underlying EBITA1) is about flat compared to the same quarter last year. Reported EBITA about 10% lower than last year due to currency effects, no income from divestments (€ 1.3 million in 2010) and weak business conditions in Poland.

Although unrest in the financial markets has resulted in increased uncertainty regarding the development of the economy, we expect that market trends will not change significantly in the fourth quarter. Due to the weak market conditions in Poland and somewhat higher financing charges and tax rate than initially foreseen, we anticipate net income from operations for full year 2011 to be approximately level with 2010. This is excluding the € 7.4 million gain on the sale of AAFM reported earlier, excluding consolidation of and costs related to the merger with EC Harris, and barring unforeseen circumstances.

¹ Underlying EBITA is excluding impact from currencies, acquisitions, reorganization costs and sale of energy assets and carbon credits.

For more information please contact Joost Slooten at +31 (0) 20 2011083, or outside office hours at +31 (0) 6 27061880 or joost.slooten@arcadis.com

About ARCADIS:

ARCADIS is an international company providing consultancy, design, engineering and management services in infrastructure, water, environment and buildings. We enhance mobility, sustainability and quality of life by creating balance in the built and natural environment. ARCADIS develops, designs, implements, maintains and operates projects for companies and governments. With 16,000 people and EUR 2.0 billion in revenues, the company has an extensive international network supported by strong local market positions. ARCADIS supports UN-HABITAT with knowledge and expertise to improve the quality of life in rapidly growing cities around the world. Please visit: www.arcadis.com