MOST NOTEWORTHY: The ocean shippers sector, Tesoro, Siemens AG and MGI Pharma were today's noteworthy upgrades:

• Bear Stears upgraded the ocean shippers sector to Market Weight from Market Underweight, citing higher day rates in the dry bulk market. The firm sees potential upside for dry bulk firms Eagle Bulk Shipping (NASDAQ: EGLE), Quintana Maritime Limited (NASDAQ: QMAR) and Ultrapetrol Ltd (NASDAQ: ULTR).
  
• Bernstein raised shares of Tesoro Corporation (NYSE: TSO) to Outperform from Market Perform and expects a rebound in West Coast refining margins.
  
• ING upgraded shares of Siemens AG (NYSE: SI) to Buy from Hold on valuation and the possibility the company may exit businesses.
  
• MGI Pharma (NASDAQ: MOGN) was upgraded at JP Morgan to Overweight from Neutral, citing expectations for a strong Q3, Aloxi re-acceleration, Dacogen growth, and Auqavan opportunity.

OTHER UPGRADES:

• UBS upgraded shares of Agnico-Eagle (NYSE: AEM) to Buy from Neutral.
  
• Banc of America upgraded Everest RE Group (NYSE: RE) and PartnerRe (NYSE: PRE) to Buy from Neutral.
  
• Calamos Asset Management (NASDAQ: CLMS) was upgraded to Neutral from Sell at Goldman Sachs.

Most Noteworthy: Acme Packet (APKT) and Ultrapetrol (ULTR) were the only two initiations on today's list.

• Acme Packet, Inc. (NASDAQ:APKT) was initiated at ThinkEquity with a Buy and $20 target and initiated at Credit Suisse First Boston with an Outperform and $21 target, both firms cited the emerging Session Border Controller market as the reason for their positive ratings.
• Ultrapetrol (Bahamas) Ltd. (NASDAQ:ULTR) was initiated at Jefferies & Co. with a Buy and $16 target due to its attractive valuation and exposure to the high growth in the South American river barge trade and the expanding PSV market.

Analyst summaries provided by TheFlyOnTheWall.com (subscription required).