Tuesday's Analysts' Upgrades and Downgrades

CHANGE IN RATINGS

Adobe Systems (ADBE Quote) rated new Outperform at Credit Suisse: Credit Suisse is initiating coverage on ADBE with an Outperform rating. Believes stock is one of the best positioned large-cap software companies. Sets $47 target price.

American Electric (AEP Quote) upgraded at Deutsche: AEP was upgraded from Hold to Buy at Deutsche Bank. $50 price target. Stock trades at an 11% discount to its peers, and the company's recent investments should pay off for investors.

CA (CA Quote) initiated at Jefferies: CA initiated at Jefferies with Hold rating. Price target starts at $27 with 2007 EPS estimates at $0.95.

Edwards Lifesciences (EW Quote) downgraded at Piper: EW was downgraded from Outperform to Market Perform at Piper Jaffray. $52 price target. Fourth quarter earnings were driver by a lower tax rate, and valve sales should remain weak in the first half of the year.

Exelon (EXC Quote) upgraded at Deutsche: EXC was upgraded from Hold to Buy at Deutsche Bank. $73 price target. Stock has already made a nice run, but still isn't fully pricing in the PECO contract.

Medimmune (MEDI Quote) downgraded at Weisel: MEDI was downgraded from Overweight to Market-weight at Thomas Weisel. Stock is up 26% since the end of June, and the company does not have many potential catalysts in 2007.

Nova Chemicals (NCX Quote) downgraded at CIBC: NCX was downgraded from Sector Perform to Underperform at CIBC. $27.50 price target. Company continues to go through a transition, and earnings should decline through 2008.

National Semiconductor (NSM Quote) downgraded at UBS: NSM downgraded to Neutral rating from Buy at UBS. Price target drops to $25 from $27.50. 2007 EPS estimates lowered to $1.07 from $1.13.

Nvidia (NVDA Quote) upgraded at JP Morgan: NVDA was upgraded from Neutral to Overweight at JP Morgan. Company should see gross margins expand over the coming quarters, as the company gains market share.