Analyst upgrades:

• Axys Tech (NASDAQ: AXYS) was upgraded to Outperform from Market Perform at Morgan Keegan on valuation.
  
• Credit Suisse upgraded Cemex (NYSE: CX) to Neutral from Underperform following the company's refinancing announcement.
  
• Patni Computer (NYSE: PTI) was upgraded to Buy from Neutral at UBS.

Analyst downgrades:

• Merriman downgraded Environmental Power (NASDAQ: EPG) to Neutral from Buy citing a lack of visibility into the company's capital raise and lowered their estimates to reflect a slippage in project schedules.
  
• Jefferies cut inVentiv Health (NASDAQ: VTIV) to Hold from Buy as they believe budget cuts at the company's client base make 2009 estimates too high. The firm lowered their target to $11 from $15.
  
• Oppenheimer downgraded RSC Holdings (NYSE: RRR) to Perform from Outperform to reflect the continued deterioration in non-residential construction and valuation following the recent rally.
• Smurfit-Stone (NASDAQ: SSCC) was lowered to Hold from Buy at Deutsche Bank.
  
• Distribucion Y Servicio (NYSE: DYS) was downgraded to Sell from Hold at Deutsche Bank.
  
• Key Energy (NYSE: KEG) was downgraded at SMH Capital to Neutral from Accumulate.

Analyst initiations:

• AECOM Technology (NYSE: ACM) was initiated with an Outperform rating and $34 target at Baird. The firm is positive on AECOM's diverse portfolio of services and global reach.
  
• Baird also initiated Checkpoint (NYSE: CKP) with a Neutral rating and $11 target, citing the weak macro environment.
  
• Thomas Weisel said Integra LifeSciences (NASDAQ: IART) has little exposure to economically sensitive areas of healthcare and has a varied mix of products that provide a platform for sustainable organic growth. Shares were initiated with an Overweight rating.
• Piper Jaffray assumed CBS Corp (NYSE: CBS) with a Neutral rating.
  
• BioMarin (NASDAQ: BMRN) was started at Stanford with a Hold rating.
  
• Websense (NASDAQ: WBSN) was initiated with an Equal Weight at First Analysis.

With its financial performance and stock price a rare bright spot in a world where most retailers are hitting 52-week lows, Wal-Mart (NYSE: WMT) is getting aggressive on the acquisition front - something that hasn't historically been part of the company's growth plan until it started its overseas expansion.

On Friday, Wal-Mart made a cash tender offer to acquire Distribución y Servicio D&S SA (NYSE: DYS), the largest grocery store chain in Chile. If all of the company's shares are tendered, which is unlikely, the deal would be valued at $2.8 billion. The company's largest shareholder, the Ibanez family, which owns a controlling stake, has already agreed to tender 23% of its shares as part of a plan to allow the company to continue to operate with its current management. Wal-Mart reserves the right to withdraw its tender offer if it is unable to lock up at least a 50% stake in the company.

Wal-Mart's strategy for its grand entrances into new markets has been to acquire a leading retail chain to begin the effort with strong market share and gain the confidence of locals.

In a press release announcing the offer, Michael Duke, Wal-Mart's vice chairman explained the move: "Moving into Chile is an important step in implementing Wal-Mart International's strategy. We continue to focus on portfolio optimization, global leverage and winning in every market. A successful tender offer will give Wal-Mart the opportunity to be a significant participant in Chile, which continues to have a strong and growing economy among South America countries."