Analyst upgrades, downgrades and initiations: CIEN, DLTR, EXPE, IBM, ZION ...

Analyst upgrades:

Piper Jaffray upgraded PetMed Express (NASDAQ: PETS) to Overweight from Neutral following the better-than-expected Q1 results. The firm raised its target on shares to $22 from $19.
Deutsche Bank upgraded International Paper (NYSE: IP) and Packaging Corp. (NYSE: PKG) to Buy from Hold to reflect stabilization in the containerboard industry. The firm raised its target price on Packaging Corp. to $24 from $14, and on International Paper to $24 from $16.
Bernstein upgraded Human Genome Sciences (NASDAQ: HGSI) to Outperform from Market Perform following the positive Phase III data for Benlysta in lupus.
IBM (NYSE: IBM) was upgraded to Hold from Sell at Societe Generale.
British Airways (OTC: BAIRY) was upgraded to Buy from Sell at Goldman.
Continental AG (OTC: CTTAY) was upgraded to Hold from Sell at Citigroup.

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.