The following ratings changes were generated on Friday, March 13.

We've downgraded BPZ Resources ( BPZ), which engages in the exploration, development and production of oil and natural gas in Peru and Ecuador, from hold to sell. This rating is driven by the generally disappointing historical performance in the stock itself.

Net income decreased significantly compared with the same quarter last year, falling from -$4.7 million to -$6.2 million. Return on equity, however, greatly increased, a signal of significant strength. BPZ's 0.1 debt-to-equity ratio is very low and below the industry average, implying very successful management of debt levels. Its 0.4 quick ratio, however, is very weak, demonstrating a lack of ability to pay short-term obligations. Earnings per share declined by 33.3% in the most recent quarter compared with the year-ago quarter, but we feel the company is poised for EPS growth in the coming year.

Shares have tumbled 83.6% over the past year, underperforming the S&P 500. Naturally, the overall market trend is bound to be a significant factor, and in one sense, the stock's sharp decline last year is a positive for future investors, making it cheaper (in proportion to its earnings over the past year) than most other stocks in its industry. But due to other concerns, we feel the stock is still not a good buy right now.

We've downgraded Central European Distribution ( CEDC), which produces, distributes, imports and exports alcoholic beverages primarily in Poland, Hungary, and the Russian Federation, from hold to sell. This rating is driven by the company's deteriorating net income, disappointing return on equity, poor profit margins, generally disappointing historical performance in the stock itself and feeble growth in its earnings per share.

Net income fell from $45.3 million in the year-ago quarter to -$82.6 million, significantly underperforming the S&P 500 and the beverages industry. ROE also greatly decreased, a sginal of major weakness. The 29.7% gross profit margin is lower than desirable, though it has increased from the year-ago period. The -18% net profit margin significantly underperformed the industry average. EPS declined 258.6% compared with the year-ago quarter, though the consensus estimate suggests that the company's two-year trend of declining EPS should reverse in the coming year.

Shares tumbled 84.1% over the past year, underperforming the S&P 500, but the stock's decline 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 China Fire & Security Group ( CFSG), which engages in the design, development, manufacture and sale of fire protection products and services for industrial customers in China, from hold to buy. This rating is driven by the company's robust revenue growth, largely solid financial position with reasonable debt levels by most measures, solid stock price performance, impressive record of earnings per share growth and compelling growth in net income. Although no company is perfect, currently we do not see any significant weaknesses which are likely to detract from the generally positive outlook.

Revenue rose by 48.7% since the year-ago quarter, exceeding the industry average of 2.4% growth and helping boost EPS by 71.4%. The company has demonstrated a two-year pattern of positive EPS growth, which we feel should continue. Net income rose 69.2% compared with the year-ago quarter, from $4 million to $6.8 million. CFSG has no debt to speak of and maintains a quick ratio of 3, demonstrating its ability to cover short-term cash needs. EPS rose 71.4%

Shares surged 29.4% over the past year, outperforming the S&P 500. Naturally, any stock can fall in a major bear market. However, in almost any other environment, this stock should continue to move higher despite the fact that it has already enjoyed nice gains in the past year.

We've upgraded RehabCare ( RHB), which provides rehabilitation program management services, from hold to buy. This rating is driven by the company's revenue growth, largely solid financial position with reasonable debt levels by most measures, solid stock price performance, growth in earnings per share and increase in net income. We feel these strengths outweigh the fact that the company shows weak operating cash flow.

Revenue rose by 13.1% since the year-ago quarter, outperforming the 6.7% industry average. EPS rose 13.8%, and we expect the company's two-year pattern of EPS growth to continue. RehabCare has a very low debt-to-equity ratio of 0.2, which is below the industry average, implying very successful management of debt levels. It also has a 1.8 quick ratio, which demonstrates its ability to cover short-term liquidity needs. Net income increased by 11.8% compared with the year-ago quarter, from $5.1 million to $5.7 million.

Shares have risen at a faster rate than the S&P 500 over the past year. Looking ahead, unless broad bear market conditions prevail, we still see more upside potential for this stock, despite the fact that it has already risen over the past year.

We've downgraded ReneSola ( SOL), which engages in the development, manufacture, and sale of solar wafers and related products in the People's Republic of China, from hold to sell. This rating is driven by the company's deteriorating net income, generally weak debt management and feeble growth in its earnings per share.

Net income significantly decreased compared with the year-ago quarter, falling from $17.5 million to -$126.6 million, significantly underperforming the S&P 500 and the semiconductors and semiconductor equipment industry. The debt-to-equity ratio of 1 is somewhat low overall but is high compared with industry average, and the 0.5 quick ratio is low, demonstrating weak liquidity. EPS declined 734.5% compared with the same quarter last year, though the consensus estimate suggests that the company's yearlong trend of declining EPS should reverse in the coming year. On the basis of ROE, ReneSola underperforms the industry average and the S&P 500.

Other ratings changes included Medifast ( MED), downgraded from buy to hold, and Neenah Paper ( NP), downgraded from hold to sell.

All ratings changes generated on March 13 are listed below.

 
Ticker
Company
Current
Change
Previous
ANH Anworth Mortgage
HOLD
Upgrade
SELL
ARKR Ark Restaurants
SELL
Downgrade
HOLD
BPZ BPZ Resources
SELL
Downgrade
HOLD
CEDC Central European Distribution
SELL
Downgrade
HOLD
CFSG China Fire & Security
BUY
Upgrade
HOLD
CSCX Cardiac Science
SELL
Downgrade
HOLD
END Endeavour International
HOLD
Upgrade
SELL
GKK Gramercy Capital
SELL
Downgrade
HOLD
GRIF Griffin Land & Nurseries
SELL
Downgrade
HOLD
MAIL IncrediMail
HOLD
Upgrade
HOLD
MED Medifast
HOLD
Downgrade
BUY
NCS NCI Building Systems
SELL
Downgrade
HOLD
NP Neenah Paper
SELL
Downgrade
HOLD
RHB Rehabcare
BUY
Upgrade
HOLD
SCG Scana
HOLD
Downgrade
BUY
SOL Renesola
SELL
Initiated
STAN Standard Parking
HOLD
Downgrade
BUY
TNL Technitrol
SELL
Downgrade
HOLD

Each business day, TheStreet.com Ratings updates its ratings on the stocks it covers. The proprietary ratings model projects a stock's total return potential over a 12-month period, including both price appreciation and dividends. Buy, hold or sell ratings designate how the Ratings group expects these stocks to perform against a general benchmark of the equities market and interest rates.

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For those reasons, we believe a rating alone cannot tell the whole story, and that it should be part of an investor's overall research.