Each weekday, 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.

Brookfield Properties ( BPO) is a publicly owned real estate investment firm. It has been downgraded to sell from hold. The company's third-quarter earnings swung to a loss of 1 cent per share compared with a gain of 9 cents a share in the same period last year. While its debt-to-equity ratio of 3.05 is very high, it is currently less than that of the industry average.

Brookfield's stock price has fallen 19.89% in the last 12 months, in part reflecting the company's sharply declining EPS when compared with the year-earlier quarter. The fact that the stock is now selling for less than others in its industry in relation to its current earnings is not reason enough to justify a buy rating at this time. Brookfield Properties had been rated a hold since TheStreet.com Ratings initiated its coverage of the company in November 2005.

Under Armour ( UA) designs, markets and distributes apparel and accessories made of synthetic microfiber. It has been downgraded to a hold from a buy.

The company's third-quarter revenue rose by 46.3% compared with the same period last year, exceeding the industry average of 12.5%. Under Armour's debt-to-equity ratio of 0.06 is below that of the industry average, implying that there has been very successful management of debt levels. Its net income rose 25.4% to $20.03 million in the third quarter compared with $15.97 million in the same period last year.

However, as a counter to these strengths, TheStreet.com Ratings find weaknesses that include premium valuation and weak operating cash flow. Under Armour was rated a hold when coverage was initiated in December 2006, and was briefly upgraded to a buy on Nov. 20 on the basis of fluctuations in its price level.

Regency Energy Partners ( RGNC) gathers, processes and transports natural gas in north Louisiana, Texas and the mid-continent region of the U.S. It has been downgraded to a hold from a buy.

The company's third-quarter revenue rose by 24.6% compared with the same period last year, outpacing the industry average of 3.8%. Regency Energy's losses narrowed to 23 cents per share in the third quarter from 25 cents a year earlier. It has reported somewhat volatile earnings recently. The company's weaknesses income poor profit margins and weak operating cash flow. Its stock has climbed 14.48% in the last 12 months, but there is currently no conclusive evidence that warrants the purchase or sale of this stock at its current price. Regency Energy had been rated a sell since coverage was initiated in March 2007.

Telecom Argentina S.A. ( TEO) provides fixed-line public telecommunications, data transmission, Internet services and publishing services in Argentina. It has been upgraded to a buy from a hold.

The company's third-quarter net income rose by 237.1% to $70.04 million from $20.78 million in the same period last year, and its earnings rose to 37 cents per share compared with 11 cents a share over the same period. Telecom Argentina's return on equity improved to 21.69% in the third quarter from negative 9.71% in the same period last year. This is a signal of significant strength within the corporation. Its revenue rose by 17.1% in the third quarter compared with the same period last year, although this trailed the industry average of 30.0%.

Powered by its earnings growth and other important driving factors, Telecom Argentina's stock price has increased by 62.8% in the past 12 months, exceeding the rise in the S&P 500 during the same period. While the sharp rise over the past 12 months has driven this stock to a price level which is relatively expensive compared with the rest of its industry, the higher price is justified given the other strengths the company shows. Telecom Argentina had been rated a hold since August 2007.

Additional ratings changes are listed below.

Stock Upgrades, Downgrades
Company Name Ticker Change New Rating Former Rating
Brookfield Properties BPO Downgrade Sell Hold
Colonial Properties Trust CLP Downgrade Sell Hold
Georgia Gulf GGC Downgrade Sell Hold
Harleysville Savings HARL Downgrade Sell Hold
Hingham Institution for Savings HIFS Downgrade Sell Hold
Sun-Times Media Group SVN Downgrade Sell Hold
Innovation Solutions ISSC Downgrade Sell Hold
IXYS IXYS Downgrade Hold Buy
Novatel Wireless NVTL Downgrade Hold Buy
Supreme Industries STS Downgrade Hold Buy
Telecom Argentina STET-Frnc TEO Upgrade Buy Hold
Franklin Bank Corp FBTX Downgrade Sell Hold
Gravity GRVY Initiation Sell n/a
Under Armour UA Downgrade Hold Buy
Vimicro International VIMC Initiation Sell n/a
Silver State SSBX Initiation Hold n/a
Regency Energy Partners RGNC Upgrade Hold Sell
China Direct CDS Initiation Hold n/a
Source: TheStreet.com Ratings

More from Investing

WATCH LIVE: Facebook CEO Mark Zuckerberg Appears Before European Parliament

WATCH LIVE: Facebook CEO Mark Zuckerberg Appears Before European Parliament

Jim Cramer on Zillow's New Business: Buying and Selling Homes

Jim Cramer on Zillow's New Business: Buying and Selling Homes

Jim Cramer: Wabtec Deal Gives General Electric Optionality

Jim Cramer: Wabtec Deal Gives General Electric Optionality

Jim Cramer on the Markets: It's Natural to Have Some Profit Taking

Jim Cramer on the Markets: It's Natural to Have Some Profit Taking

Video: Jim Cramer on the Markets, Oil, General Electric, Zillow and Micron

Video: Jim Cramer on the Markets, Oil, General Electric, Zillow and Micron