Analyst upgrades:

• FBR Capital upgraded AutoZone (NYSE: AZO) to Market Perform from Underperform on valuation following the company's Q4 results but lowered its target on shares to $134 from $137.
• Citigroup upgraded Calpine (NYSE: CPN) to Buy from Hold on valuation following Wednesday's sell-off. The firm believes Harbinger's share sale reflects an issue with the shareholders, not with the company, and raised its price target on the stock to $16.50 from $13.
• Credit Suisse upgraded Knight Transportation (NYSE: KNX) to Neutral from Underperform and raised its target to $17 from $16 based on valuation and the improved freight environment.
• Citrix Systems (NASDAQ: CTXS) was upgraded to Conviction Buy from Buy at Goldman.
• Webster Financial (NYSE: WBS) was upgraded to Outperform from Sector Perform at RBC Capital.
• Dr. Reddy's Labs (NYSE: RDY) was upgraded to Overweight from Equal Weight at Morgan Stanley.

Analyst upgrades:

• Morgan Keegan upgraded Motorola (NYSE: MOT) to Outperform from Market Perform due to the increased visibility of Android-based launches, as well as the stock's valuation.
• OfficeMax (NYSE: OMX) was upgraded to Buy from Hold by Citigroup, which cited the company's stabilizing sales trend, accelerating share gains, and valuation.
• Kaufman Bros. upgraded iRobot (NASDAQ: IRBT) to Buy from Hold on valuation.
• Cancaccord upgraded Rio Tinto (NYSE: RTP) to Buy from Hold citing the turnaround in the aluminum business and its exposure to copper.
• Wells Fargo upgraded Smith & Nephew (NYSE: SNN) to Market Perform from Underperform.
• BT Group (NYSE: BT) was upgraded to Neutral from Reduce by Nomura.
• Societe Generale raised L'Oreal (OTC: LRLCY) to Buy from Sell.
• Franklin Resources (NYSE: BEN) was upgraded to Buy from Hold by Sandler O'Neill.

Analyst upgrades:

• Goldman added McDonald's (NYSE:MCD) to its Conviction Buy List as they believe the company will beat their earnings expectations over the next couple quarters. Note that Burger King (NYSE:BKC) was removed from the list.
  
• Baird upgraded Woodward Govenor (NASDAQ:WGOV) to Outperform from Neutral citing increased confident in its outlook following the better-than-expected Q1 report.
  
• Citigroup upgraded Harley-Davidson (NYSE:HOG) to Hold from Sell and removed shares from their Top Picks Live List as a Sell as they believe current expectations are very low following the recent weakness. Citigroup lowered their target price to $13 from $18.
• Ford (NYSE:F) and Lear (NYSE:LEA) were upgraded to Hold from Sell at Deutsche Bank.
  
• KT Corp (NYSE:KTC) was raised to Overweight from Neutral at HSBC.
  
• Ryanair (NASDAQ:RYAAY) was upgraded to Hold from Sell at Collins Stewart and to Buy from Neutral at UBS.

Analyst downgrades:

• Goldman removed Burger King (NYSE:BKC) from its Conviction Buy List citing recent share strength. Note that McDonald's (NYSE:MCD) was added to the list.
  
• Keefe Bruyette downgraded shares of Och-Ziff Capital (NYSE:OZM) to Market Perform from Outperform to reflect the company's near-term headwinds. The firm lowered their target to $5 from $6.50.
  
• Morgan Stanley downgraded Freeport-McMoRan (NYSE:FCX), Alcoa (NYSE:AA), and Century Aluminum (NASDAQ:CENX) to Equal Weight from Overweight as they believe industrial metals will be depressed through next year.
• Air France (Other OTC:AFLYY) was downgraded to Sell from Neutral at UBS.
  
• Wal-Mart (NYSE:WMT) was lowered to Neutral from Outperform at Credit Suisse.
  
• Radware (NASDAQ:RDWR) was cut at Argus to Hold from Buy.

Analyst initiations:

• Merriman initiated Suntech (NYSE:STP) with a Sell rating. The firm is concerned by the company's debt load and narrowing maturity and thinks further cost reduction in China could be a challenge. The firm believes a fair price target range is $3.50-$4.50 per share.
  
• JMP Securities views Google (NASDAQ:GOOG) as a long-term "must buy" given its dominant market position, strong balance sheet, and low valuation. Shares were initiated with an Outperform rating and $400 target.
  
• Auriga started Micron (NYSE:MU) with a Buy rating and $5 target. The firm expects DRAM oversupply to ease in the second half of 2009 and believes Micron will not burn significant cash this year.
• Qualcomm (NASDAQ:QCOM) was initiated at Morgan Stanley with an Equal Weight rating and $41 target.
  
• Core Laboratories (NYSE:CLB) was initiated with a Buy rating and $80 target at Wunderlich.
  
• Mylan (NASDAQ:MYL) was started with a Buy rating and $16 target at Citigroup.

MOST NOTEWORTHY: Nvidia, Air France and UnitedHealth were today's noteworthy downgrades:

• JP Morgan downgraded Nvidia (NASDAQ:NVDA) to Neutral from Overweight following the company's lowered guidance.
  
• Deutsche Bank cut Air France (Other OTC:AFLYY) to Sell from Hold as they believe consensus revenue estimates need to come down.
  
• Following UnitedHealth's (NYSE:UNH) lowered guidance, UBS said there is "little hope" for improvement in 2009 and that the company has above average exposure to the Medicare segment, which is being politically pressured. UBS downgraded shares to Neutral from Buy.

OTHER DOWNGRADES:

• Aetna (NYSE:AET) and Health Net (NYSE:HNT) were downgraded to Sell from Neutral at Goldman.
• Dice Holdings (NYSE:DHX) was lowered at Wachovia to Market Perform from Outperform.
  
• Zhone (NASDAQ:ZHNE) was downgraded to Source of Funds from Buy at ThinkPanmure.

MOST NOTEWORTHY: Lloyds TSB Group, OmniVision and National Instruments were today's noteworthy downgrades:

• Credit Suisse downgraded shares of Lloyds TSB Group (NYSE: LYG) to Underperform from Neutral as they see greater mortgage risk and capital issues.
  
• Oppenheimer cut OmniVision (NASDAQ: OVTI) to Perform from Outperform to reflect challenging conditions in the low-end Chinese handset market.
  
• Thomas Weisel downgraded shares of National Instruments (NASDAQ: NATI) to Market Weight from Overweight as they expect EPS growth as operating margins approach cyclical peaks.

OTHER DOWNGRADES:

• Air France-KLM (OTC: AFLYY) was cut to Hold from Buy at Citigroup and to Neutral from Buy at Merrill.
  
• Exelon (NYSE: EXC) and Edenor (NYSE: EDN) were both downgraded at Citigroup to Hold from Buy.
  
• Goldman lowered Grupo Aeroportuario del Pacifico (NYSE: PAC) to Neutral from Buy.