By Jeffrey H. Birnbaum Washington Post Staff Writer Saturday, June 17, 2006 The Washington lobbying firm enmeshed in a federal investigation of Rep. Jerry Lewis (R-Calif.), chairman of the powerful House Appropriations Committee, is breaking up because of publicity surrounding the probe, the company said yesterday. The firm, Copeland Lowery Jacquez Denton & White, has been a major player on K Street, particularly in winning narrow appropriations, known as earmarks, for military contractors, municipalities and others. Federal investigators last month subpoenaed many of the firm's clients to learn more about the relationship between Lewis and former representative Bill Lowery (R-Calif.), a partner in the firm since 1993 who is a friend and financial supporter of his.