ByJohn S. McClenahen Merrill Lynch & Co.'s corporate symbol is a bull, but during the last four months its earnings projections for 2001 have become increasingly bearish. The New York-based securities firm now expects S&P 500 operating EPS (earnings-per-share) to be flat for this year. "We expect year-on-year growth rates for earnings to be negative during the first half of the year, then picking up by the end of the year," relates Bruce Steinberg, Merrill Lynch's chief economist. This comes in the context of a revised GDP forecast, with Merrill Lynch now estimating the current calendar quarter's growth rate at 1.5% and the second quarter's between 2% and 2.5%. For the full year, its projection is 2.5%, down from the previous forecast of 2.9%.