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.

While the ratings model is quantitative, it uses both subjective and objective elements. For instance, subjective elements include expected equities market returns, future interest rates, implied industry outlook and company earnings forecasts. Objective elements include volatility of past operating revenue, financial strength and company cash flows.

The rating does not incorporate all of the factors that can alter a stock's performance. For example, it doesn't always factor in recent corporate or industry events that could affect the stock price, nor does it include recent technology developments and competitive dynamics that may affect the company.

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

American Express ( AXP - Get Report), together with its subsidiaries, operates as a payments, network and travel company worldwide. It has been downgraded to hold from buy.

The company's third-quarter earnings increased by 18.4% to 90 cents a share, up from 76 cents per share in the same period last year. American Express has demonstrated a pattern of positive EPS growth over the past two years, a trend TheStreet.com Ratings feel should continue. Net income increased 10.3% to $1.07 billion in the third quarter from $967 million in the same period last year. While the company's debt-to-equity ratio of 6.38 is very high, it is nonetheless lower than that of the industry average. American Express' stock price has fallen by 24.6% in the last 12 months.

Turning toward the future, the fact that the stock has come down in price is not necessarily a negative; it could be one of the factors that may help make it attractive down the road. Right now, however, we believe that it is too soon to buy. American Express has been rated a buy since March 2006.

Companhia de Bebidas das Americas-AmBev ( ABV) produces and sells beer and nonalcoholic soft drinks principally in Latin America. It has been downgraded to hold from buy.

The company's third-quarter revenue rose 38.7% compared with the same period last year, outpacing the industry average of 9.8%. Its earnings increased 67.6% to 57 cents a share in the third quarter, up from 34 cents per share in the same period last year, continuing a pattern of positive EPS growth over the past two years. This is a trend we expect to continue.

Companhia de Bebidas' stock price has gone up by 47.03% in the last 12 months, driving it to a price level that is relatively expensive compared with the rest of its industry. The reduced upside potential is not good enough to warrant further investment at this time. TheStreet.com Ratings also finds that the company has not been very careful in the management of its balance sheet. Companhia de Bebidas had been rated a buy since November 2007.

Host Hotels & Resorts ( HST - Get Report) owns or has controlling interests in upscale and luxury hotels under the Marriott, Ritz-Carlton, Hyatt, Four Seasons, Hilton, Fairmont and Westin names. It has been downgraded to hold from buy.

The company's third-quarter earnings rose to 17 cents a share from five cents per share in the same period last year, and it has demonstrated a two-year pattern of positive EPS growth. This trend is likely to continue. Host Hotels' net income rose 142.5% to $97 million in the third quarter from $40 million in the same period last year. However, the company has shown poor profit margins, and its stock price has fallen by 32.5% in the past 12 months.

While the decline has dropped it to a level where it is now cheaper than most other stocks in its industry, we feel that, because other concerns, the stock is not a good buy right now. Host Hotels had been rated a buy since July 2006.

BJ Services Company provides pressure pumping and oilfield services for the petroleum industry worldwide. It has been downgraded to hold from buy.

The company's fourth-quarter net income decreased 17.2% compared with the same period last year and 6.3% for the year, because of continued pricing pressures, a decline in Canadian drilling activities and margin compression as well as higher interest expenses. BJ Services is expanding its business through acquisitions, with recent purchases that include the capillary tubing units from Allis-Chalmers Energy , and Norson Service Ltd., which provides sub-sea pipeline commissioning and umbilical testing services to select offshore markets.

BJ Services' performance is dependent on the number of rigs operational in the market, which is in turn determined by the quantum of drilling and related activities, which are cyclical in nature. The company had been rated a buy since January 2006.

Mirant produces and sells electricity in the U.S. and the Caribbean. It has been upgraded to buy from hold.

The company's third-quarter net income swung to a profit of $775 million compared with a loss of $26 million in the same period last year. In addition, its debt-to-equity ratio of 0.48 is low and beneath that of the industry average, implying that there has been successful management of debt levels. Along with this, the company maintains a quick ratio of 5.97, which clearly demonstrates the ability to cover short-term cash needs.

Mirant has also demonstrated a pattern of positive EPS growth over the past two years, although we anticipate under performance relative to this pattern in the coming years. These strengths outweigh the company's weak operating cash flow.

Additional ratings changes are listed below.

StockUpgrades, Downgrades
Company Name Ticker Change New Rating Former Rating
ADC Telecommunications ADCT Downgrade Hold Buy
American Express AXP Downgrade Hold Buy
Barr Pharmaceuticals BRL Upgrade Buy Hold
BJ Services BJS Downgrade Hold Buy
BJ's Wholesale BJ Downgrade Hold Buy
Caledonia Mining CALVF Upgrade Hold Sell
Cia de Bebidas ABV Downgrade Hold Buy
Ellis Pery PERY Downgrade Hold Buy
FNB FNB Downgrade Hold Buy
Famous Daves of America DAVE Downgrade Hold Buy
Flexsteel Industries FLXS Downgrade Hold Buy
Host Hotels & Resort HST Downgrade Hold Buy
J&J Snack Food JJSF Downgrade Hold Buy
Epoch Holding EPHC Downgrade Hold Buy
Lear LEA Downgrade Sell Hold
Microsemi MSCC Downgrade Hold Buy
Northwest NWSB Downgrade Hold Buy
One Liberty Properties OLP Downgrade Hold Buy
Pep Boys PBY Downgrade Sell Hold
PMC Commercial Trust PCC Downgrade Hold Buy
Prosperity Bancshares PRSP Downgrade Hold Buy
Relm Wireless RWC Downgrade Hold Buy
Tech Ops Sevcon TO Downgrade Hold Buy
Pinnacle Financial Partners PNFP Downgrade Hold Buy
CB Richard Ellis CBG Downgrade Hold Buy
Cascade Microtech CSCD Upgrade Hold Sell
Bois d'Arc Energy BDE Downgrade Hold Buy
Double Hull Tankers DHT Upgrade Hold Sell
Mirant MIR Upgrade Buy Hold
Incredimail MAIL Downgrade Sell Hold
Smart Modular Technologies SMOD Upgrade Hold Sell
International Royalty ROY Upgrade Hold Sell
Source: TheStreet.comRatings

This article was written by a staff member of TheStreet.com Ratings.