Top Analyst Upgrades and Downgrades (ALTR, MT, DF, GM, GT, GOOG, HPQ, HON, IMGN, KSU, MXIM, MON, NAV, OMX, TRIP, VR, XRX, YHOO)

Source: Jon Ogg
These are some of the top analyst upgrades, downgrades and initiations seen from Wall St. research calls this Thursday.

Altera Corp. (NASDAQ: ALTR) cut to Hold at Jefferies.

ArcelorMittal (NYSE: MT) cut to Sell at Goldman Sachs.

Dean Foods Co. (NYSE: DF) raised to Outperform at BMO.

General Motors Co. (NYSE: GM) started as Hold at Stifel Nicolaus.

Goodyear Tire & Rubber Co. (NYSE: GT) raised to Buy at Goldman Sachs.

Google Inc. (NASDAQ: GOOG) reiterated Buy and raised target to $875 at Argus.

Hewlett-Packard Co. (NYSE: HPQ) cut to Underperform at Jefferies.

Honeywell International Inc. (NYSE: HON) started as Buy at BofA/ML.

Immunogen Inc. (NASDAQ: IMGN) started as Sell at UBS.

Kansas City Southern (NYSE: KSU) reiterated outperform but raised target to $100 at Credit Suisse.

Maxim Integrated Products Inc. (NASDAQ: MXIM) raised to Buy at Jefferies.

Monsanto Co. (NYSE: MON) raised to Outperform at Wells Fargo.

Navistar International Corp. (NYSE: NAV) named Bear of the Day at Zacks.

OfficeMax Inc. (NYSE: OMX) named Bull of the Day at Zacks.

TripAdvisor Inc. (NASDAQ: TRIP) cut to Sector Perform at RBC.

Validus Holdings Ltd (NYSE: VR) started as Outperform at Credit Suisse.

Xerox Corp. (NYSE: XRX) reiterated Buy with $13 target at Argus.

Yahoo! Inc. (NASDAQ: YHOO) started as Buy with $22 target at Goldman Sachs.