MOST NOTEWORTHY: Roche Holdings AG (RHHBY), US Steel Corp (X) and Penn National Gaming (PENN) topped today's list of most notable downgrades:

• Bear Sterns downgraded Roche Holdings AG (OTC: RHHBY), to Peer Perform from Outperform after they lowered estimates to reflect higher taxes, slowing pharmaceutical sales, increased payments to third-party groups and reduced diagnostics profitability. Bernstein also downgraded Roche to Market Perform from Outperform.

• CIBC downgraded U.S. Steel Corp (NYSE: X) to Sector Performer from Sector Outperformer based on valuation. Bank of America also downgraded shares to Neutral from Buy with a $90 target citing the good news is reflected in the valuation.

• Penn National Gaming (NASDAQ: PENN) was downgraded to Hold from Buy on valuation with a $48.50 target.

OTHER DOWNGRADES:

• Silicon Image Inc (NASDAQ: SIMG) was downgraded to Underperform from Hold with a $7.50 target at Jefferies to reflect slow 1.3 HDMI adoption, aggressive 2007 guidance and deteriorating ASPs and margins; the firm recommends investors sell the stock. Silicon Image was also downgraded to Hold from Buy at Stanford and Needham, to Sector Performer from Outperformer at CIBC and to Neutral from Buy at DA Davidson.

• Spectrum Brands Inc (NYSE: SPC) was downgraded to Underweight from Neutral with a $7 target at Prudential following the company's disappointing first quarter results.

• Bear Stearns downgraded Forward Air Corp (NASDAQ: FWRD) to Underperform from Peer Perform.

• AG Edwards downgraded Callaway Golf Corp (NYSE: ELY) to Hold from Buy on valuation.

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