ATG To Present At The SG Cowen 33rd Annual Technology Conference, Presentation to be Webcast Live Over the Internet on June 1

Business Wire, May 23, 2005

CAMBRIDGE, Mass. -- ATG (Art Technology Group, Inc., NASDAQ: ARTG), the software provider behind the most consistent and relevant marketing, commerce, and service experiences, today announced that the company is scheduled to present at the SG Cowen 33rd Annual Technology Conference on Wednesday, June 1, 2005 at 1:00 p.m. (ET). At the conference, Chief Executive Officer Bob Burke and Chief Financial Officer Ed Terino will provide insight about the company's business strategy and its recent financial results.

ATG's presentation will be webcast live over the Internet. Interested parties may tune in to the live presentation by visiting the "For Investors" section of ATG's web site at www.atg.com.

About ATG

ATG (Art Technology Group, Inc., NASDAQ: ARTG) delivers innovative software to help high-end consumer-facing companies create a richer, more adaptive interactive experience for their customers and partners throughout the lifecycle of marketing, commerce, and customer service, and across the Web, e-mail and call centers. ATG has delivered category-leading e-business solutions to many of the world's best known brands including A&E Networks, Airbus, American Airlines, American Eagle Outfitters, AT&T Wireless, Best Buy, Boeing, France Telecom, Friends Provident, GE, Hewlett-Packard, HSBC, InterContinental Hotels Group, Kingfisher, Merrill Lynch, Neiman Marcus, Philips, Procter & Gamble, SBC, T-Mobile, Target, US Army, US Federal Aviation Administration, Warner Music, Wells Fargo, and Yahoo! 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) 2005 Art Technology Group, Inc. ATG and Art Technology Group are registered trademarks of Art Technology Group, Inc. All other product names, service marks, and trademarks mentioned herein are trademarks of their respective owners.