New York--B-to-b ad agency Greco Ethridge Group Inc. has shut down, according to sources. Company officials did not return repeated phone calls. Greco Ethridge, which reported 2000 revenues of $17.4 million, had clients including CMP Media L.L.C.'s InformationWeek, Deloitte & Touche L.L.C. and application service provider Interpath. Between 1999 and 2000, the agency grew its revenues by 60% and its employee base by 25%, and it announced aggressive expansion plans, including the opening of a London office. The company has closed its doors, sources said, and its Web site is no longer operational. InformationWeek and Interpath did not return phone calls.