Change in Ratings

Aspen Insurance ( AHL) upgraded at Goldman Sachs to buy from neutral based on valuation. See attractive risk/reward profile with shares trading at 0.87 times last reported book value.

American International Group ( AIG) downgraded at Goldman to neutral from buy based on balance sheet pressures and dilutive capital raises. See lower investment income and higher general insurance accident-loss ratios. Price target cut to $45 from $59.

Commercial Metals ( CMC) initiated at UBS with buy rating. Price target starts at $37 and fiscal year 2008 EPS estimates begin at $2.05.

Dollar Tree ( DLTR) upgraded at JPMorgan to neutral from underweight. Most of the negative catalysts have played out since the CFO left last October.

DRS Technologies ( DRS) downgraded at Credit Suisse from outperform to neutral with a $73.50 price target. Rumored acquisition by Finmeccanica more than 50% likely to happen, but the potential price remains unclear.

El Paso ( EP) upgraded at JPMorgan from neutral to overweight. Valuation call, especially as fundamentals improved in the first quarter.

Imclone ( IMCL) downgraded at Morgan Stanley from equal-weight to underweight with a $38 price target. Do not expect ASCO data to meet expectations. Erbitux sales estimates also cut.

Markel ( MKL) downgraded at Goldman Sachs to sell from neutral based on view that shares will underperform peers as investors flock to beaten down names with lower multiples.

Marsh & McLennan ( MMC) upgraded at Goldman Sachs to neutral from sell based on improving sentiment towards turnaround efforts. Note investors are giving management the benefit of the doubt.

Transatlantic Holdings ( TRH) downgraded at Goldman Sachs to sell from neutral. See lower ROE compared to peers, along with higher multiple. Believe investors will look to other unfairly punished names with more attractive multiples over next 12 months.

Stock Comments/EPS Changes

Alcoa ( AA) target raised at Morgan Stanley. Shares of AA now seen reaching $47. Company is pulling back on investment, but should continue to benefit from rising aluminum prices. Overweight rating.

Atwood Oceanics ( ATW) numbers raised at Jefferies. Price target jumps to $102 from $90 while 2009 EPS estimates lift to $10.86 from $10.72. Reiterates hold rating.

PetroQuest Energy ( PQ) target raised at Jefferies to $23 from $12 while 2008 EPS estimates dip to $1.16 from $1.19. Reiterates hold rating.

St. Mary Land & Exploration ( SM) numbers raised at Jefferies. Price target upped to $60 from $50 while 2008 EPS estimates lift to $4.36 from $4.24. Reiterates buy rating.

Wal-Mart ( WMT) target boosted at Citigroup to $67. International division is more streamlined, and should help drive future profit growth. Buy rating.

This article was written by a staff member of TheStreet.com Ratings.

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