The following ratings changes were generated on Tuesday, March 3.We've downgraded investment management firm AllianceBernstein Holding ( AB) from hold to sell, driven by its feeble growth in its earnings per share, weak operating cash flow and generally disappointing historical performance in the stock itself. The company has experienced a steep decline in earnings per share of 74.5% in the most recent quarter compared with the year-ago quarter, and we anticipate that its two-year trend of declining EPS should continue in the coming year. Net operating cash flow decreased by 49.4% to $52.5 million compared with the same quarter last year, and return on equity also decreased, a sign of weakness within the company. Net income feel 73.9%, from $92.2 million to $24 million. Shares tumbled 81.9% over the year, underperforming the S&P 500, but that should not necessarily be interpreted as a negative; it could be one of the factors that may help make the stock attractive down the road. Right now, however, we believe that it is too soon to buy. We've upgraded retail propane distributor AmeriGas Partners ( APU) from hold to buy, driven by its compelling growth in net income, notable return on equity, expanding profit margins, growth in earnings per share and relatively strong performance when compared with the S&P 500 during the past year. We feel these strengths outweigh the fact that the company has had generally poor debt management on most measures that we evaluated. Net income increased by 128.3% compared with the same quarter last year, from $54.3 million to $124 million, significantly outperforming the S&P 500 and the gas utilities industry. ROE also greatly increased, a signal of significant strength. AmeriGas has a 38.5% gross profit margin, which we consider to be strong, and its net profit margin of 17% significantly outperformed the industry average. EPS rose significantly compared with the year-ago quarter, and though it has reported volatile earnings lately, we feel the company is poised for EPS growth in the coming year. Revenue fell by 2.8% since the year-ago quarter.