Analyst downgrades:

• Collins Stewart downgraded AstraZeneca (NYSE: AZN) to Sell from Hold as it believes investor attention could turn towards the Crestor patent challenge and that takeover speculation will not amount to a deal.
• Goldman downgraded Portland General Electric (NYSE: POR) to Neutral from Buy but raised its target to $23 from $22. The firm cites valuation and concerns regarding guidance for the downgrade.
• Soleil downgraded Western Refining (NYSE: WNR) to Hold from Buy on concerns debt covenants could be broken in Q1 of 2010. The firm lowered its target price on shares to $8.
• ProLogis (NYSE: PLD) was downgraded to Perform from Outperform at Oppenheimer.
• American Capital (NASDAQ: AGNC) was downgraded to Underperform from Neutral at BofA/Merrill.
• Synovus (NYSE: SNV) was downgraded to Underperform from Market Perform at FBR Capital.

Analyst initiations:

• Citigroup expects Coca-Cola (NYSE: KO) to post better earnings growth in 2010, leading to multiple expansion. The firm started shares with a Buy rating and $61 target.
• Stephens believes Myriad (NASDAQ: MYGN) is well positioned in the specialty cancer testing market. The firm initiated shares with an Overweight rating and $36 target.
• Pali Capital assumed Charles Schwab (NASDAQ: SCHW) with a Neutral rating. The firm prefers to wait for a raising interest rate cycle or a more attractive valuation to put new money to work in Charles Schwab shares.
• Hewlett-Packard (NYSE: HPQ) was initiated with a Buy rating and $56 target at Brigantine.
• Evercore Partners (NYSE: EVR) was initiated with an Outperform rating at William Blair.
• MasterCard (NYSE: MA) was initiated with a Positive rating and $244 target at Susquehanna.