Catalyst Semiconductor Inc., a Santa Clara, Calif.-based developer of analog, mixed-signal and nonvolatile memory semiconductors, said yesterday that Thomas E. Gay III, vice president of finance and administration and chief financial officer, is leaving the company, effective May 31. Catalyst President and CEO Gelu Voicu said in a statement that the search for Gay's successor is underway and that Gay will assist in the transition and in completing the audit for fiscal 2007, which ended April 30. The company is scheduled to report fourth-quarter results on June 7.