Moody's Investors Service has added Jim Brennan as a collateralized debt obligation analyst in its New York office. He will report to Isaac Efrat, managing director, and will rate various CDO transactions from cash-flow deals to synthetic transactions, including arbitrage and market value deals. Brennan says he started two weeks ago and that his position is a newly created one. He joins from Mutual of Omaha in Nebraska, where he reported to Donna Ennis, v.p. of structured securities. Mary Kavan has replaced him there, he says.