Analyst downgrades:

• JMP Securities downgraded Idenix Pharma (NASDAQ: IDIX) to Market Perform from Outperform given near-term cash needs.
• Citigroup downgraded Zions Bancorp. (NASDAQ: ZION) to Sell from Hold and lowered its rating to $9 from $12. The firm downgraded shares based on increased credit and capital concerns.
• Stifel Nicolaus downgraded Black Box (NASDAQ: BBOX) to Hold from Buy citing risk to the Nortel business given Avaya's acquisition of Nortel's Enterprise Solutions business.
• DHT Maritime (NYSE: DHT) was downgraded to Neutral from Overweight at JPMorgan.
• Enbridge Energy (NYSE: EEP) was downgraded to Neutral from Buy at BofA/Merrill.
• Holly Energy (NYSE: HEP) was downgraded to Neutral from Conviction Buy at Goldman.

Analyst initiations:

• Deutsche Bank believes Expedia (NASDAQ: EXPE) is well positioned to benefit as a distribution channel for travel suppliers seeking to fill rooms. The firm started shares with a Buy rating and $19 target.
• Deutsche Bank also initiated Arrow Electronics (NYSE: ARW) with a Hold rating and $24 target. The firm prefers to wait for operating margin improvement before getting positive on Arrow shares.
• Soleil expects Ciena (NASDAQ: CIEN) to report better than expected earnings in 2010 and 2011 due to new product cycles with strong gross margins. Shares were assumed with a Buy rating and $14.50 target.
• Dollar Tree (NASDAQ: DLTR) was reinstated with a Buy rating and $50 target at BofA/Merrill.
• Bayer (OTC: BAYRY) was initiated with an Outperform rating at Credit Suisse.
• Martek Bio (NASDAQ: MATK) was initiated with a Buy rating and $29 target at B. Riley.