Among the stock activity stories for Wednesday, Dec. 16, from AP Financial News:

NEW YORK (AP) ¿ Shares of Adobe Systems Inc. climbed in midday trading after the company said demand for its software picked up strongly in November.

MILWAUKEE (AP) ¿ Shares of wine maker Constellation Brands Inc. tumbled after a downgrade amid news the company was being sued by its Mexican-based partner in a joint venture.

BOSTON (AP) ¿ Shares of Charles Schwab Corp. rose after a Deutsche Bank Securities analyst upgraded the retail brokerage's stock and another analyst initiated coverage with a favorable rating.

CHICAGO (AP) ¿ Shares of restaurant owner Darden Restaurants Inc., which operates Olive Garden, Red Lobster and Longhorn Steakhouse, climbed after an analyst upgraded the stock.

NEW YORK (AP) ¿ Shares of industrial equipment maker Roper Industries Inc. rose after Standard & Poor's said it will add the company to the S&P 500 index next week.

NEW YORK (AP) ¿ Shares of CardioNet Inc. gained ground after a Leerink Swann Research analyst upgraded the stock, citing an "encouraging" outlook for the wireless heart-monitoring device maker.

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