ATG Helps Volvo Global Information Technology Enhance World-Class Support; IT Solutions Provider Chooses Wisdom-Enabled ATG Knowledge to Empower Workforce of 3,500 Support Professionals

CAMBRIDGE, Mass.--April 3, 2006--ATG (Art Technology Group, Inc., NASDAQ: ARTG) whose technology powers leading e-commerce sites and corresponding e-marketing and customer service, today announced that Volvo Global Information Technology (IT), a wholly-owned subsidiary of AB Volvo, has selected ATG Knowledge to enable its support staff of nearly 3,500 personnel to locate, leverage, capture and communicate critical information. Integrating ATG Knowledge with the company's legacy CRM system empowers Volvo Global IT's front-line support staff to significantly reduce problem resolution time, resulting in a more efficient, cost-effective support service.

"Often as enterprises expand, critical knowledge becomes spread across the organization within legacy systems, Web sites, databases and other documents," said Cliff Conneighton, senior vice president of marketing, ATG. "Rapid, efficient access to this information can be the difference between an unhelpful support call and an extremely positive experience that enhances a company's overall relationship with a customer. Companies truly committed to providing world-class service and support, such as Volvo, use ATG Wisdom-enabled Service because it provides better, more relevant answers, driving more loyal and profitable customer relationships."

ATG Knowledge is the company's industry-leading knowledge management platform for call center-assisted customer service, and is part of the new Wisdom-enabled ATG Service Suite, a comprehensive set of applications that provides a full-featured, adaptively customized environment for managing all forms of customer service interactions with individual attention. By employing industry-leading best practices and state-of-the-art tools for finding information, ATG Knowledge empowers agents to actively take advantage of all knowledge located across the extended enterprise. Using this holistic approach, ATG allows companies to ensure the continuity of their customers' experience across the entire marketing, sales and service lifecycle, regardless of whether they make contact via telephone, e-mail, Web form or Web self-service.

About ATG

ATG (Art Technology Group, Inc., NASDAQ: ARTG) makes the software that the world's most customer-conscious companies use to create a more relevant and consistent customer experience, throughout the marketing, commerce, and service lifecycle, and across the Web, e-mail, call center, and mobile channels. Offering an alternative to the traditional silo-based approach to customer-facing applications, ATG Wisdom(TM) is the company's strategy for delivering a seamless, more compelling, and mutually valuable experience to each customer and segment. The company fulfills this strategy by providing fully integrated best-of-breed product suites installed on-premise or delivered on-demand. ATG's solutions power over 600 major brands, including A&E Networks, Airbus, American Airlines, American Eagle Outfitters, Best Buy, Boeing, Cingular Wireless, DirecTV, France Telecom, Friends Provident, Hewlett-Packard, Hotels.com, Hyatt Hotels, HSBC, InterContinental Hotels Group, Kingfisher, Louis Vuitton, Merrill Lynch, Neiman Marcus, Philips, Procter & Gamble, Symantec, T-Mobile, Target, US Army, US Navy, Warner Music, and Wells Fargo. The company is headquartered in Cambridge, Massachusetts, with additional locations throughout North America, Europe, and Asia. For more information about ATG, please visit www.atg.com.

(c) 2006 Art Technology Group, Inc. ATG and Art Technology Group are registered trademarks and ATG Wisdom is a trademark of Art Technology Group, Inc. All other product names, service marks, and trademarks mentioned herein are trademarks of their respective owners.

This press release contains forward-looking statements for purposes of the safe harbor provisions under The Private Securities Litigation Reform Act of 1995. These statements involve known and unknown risks and uncertainties that may cause ATG's actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by such forward-looking statements. Important risk factors affecting ATG's business generally may be found in its periodic reports and registration statements filed with the Securities and Exchange Commission at www.sec.gov. Risk factors related to the subject matter of this press release include the possibility that the ATG product deployment will not be successful, on time or significantly enhance the user's Internet experience or will not increase customer revenue across brands; that those customers leveraging ATG won't have the opportunity to increase revenue and decrease future costs; the need to adapt to rapid changes so products do not become obsolete; the possibility of errors in ATG's software products; the possibility that the solution will not make customer implementations faster or more flexible or permit the customer to meet its customer-facing or infrastructure requirements; that the ATG product will not continue to be integrated with third-party applications servers or will not support all Web services enabled systems; that ATG's product strategy may change in the future; and the risks and costs of intellectual property litigation. ATG undertakes no obligation to update any of the forward-looking statements after the date of this press release.