Holding(s) in Company

Chéserex, Switzerland, 23 December 2009: Pursuant to Art. 9 and 21 of the Stock Exchange Ordinance-FINMA, Adecco S.A. has received the following notification: 1. Name of the listed company:Adecco S.A. 2. Proportion of voting rights held (total holdings in percent):below 3% 3. Identity of those involved: Group consisting of Credit Suisse Group AG, Paradeplatz 8, P.O. Box, 8070 Zurich, Switzerland, and its subsidiaries: Credit Suisse Group AG indirectly via its subsidiaries Clariden Leu Holding AG, Bahnhofstrasse 32, 8001 Zurich, Switzerland (indirectly via Clariden Leu AG, Bahnhofstrasse 32, 8001 Zurich, Switzerland), and Credit Suisse AG, Paradeplatz 8, Postfach, 8070 Zurich, Switzerland, directly and indirectly via their subsidiaries Credit Suisse International, One Cabot Square, London, E14 4QJ, UK, and Credit Suisse Life (Bermuda) Ltd., Argyle House, 41 A, Cedar Avenue, Hamilton HM 12, Bermuda, and Credit Suisse Life & Pensions AG, Mühleholz 3, FL-9490 Vaduz, and Credit Suisse (International) Holding AG, Bahnhofstrasse 17, 6300 Zug, Switzerland (indirectly via Credit Suisse Investments (UK), One Cabot Square, London E14 4QJ, UK, indirectly via Credit Suisse Investment Holdings (UK), One Cabot Square, London E14 4QJ, UK, indirectly via Credit Suisse Securities (Europe) Limited, One Cabot Square, London, E14 4QJ, UK). 4. Nature of the agreement:n.a. 5. Time (date) of acquisition, sale or understanding through which the shareholding reached, exceeded or fell below the percentage threshold: 18 December 2009; Sale & non-execution of financial instruments. 6. Representative of the Group Credit Suisse, Brandschenkestrasse members: 25, 8002 Zurich, Switzerland Ms. Cathrine Zgraggen, Phone +41 44 334 79 53, Fax +41 44 333 59 50 Contact: Adecco Investor Relations: Tel: +41 44 878 89 89 E-Mail:investor.relations@adecco.com [HUG#1367554] Below 3% Credit Suisse Group AG: http://hugin.info/136572/R/1367554/334434.pdf