Monday’s biggest gaining and declining stocks

CHICAGO (MarketWatch) � Shares of the following companies made notable moves in the U.S. stock market on Monday:

Advancers

Ardea Biosciences �soared almost 52% after the company agreed to be acquired by the U.K.�s AstraZeneca AZN �for $1.26 billion. AstraZeneca�s U.S.-listed shares fell 1.5%. Amylin Pharmaceuticals �jumped 13.7% on speculation of another deal in the sector. Read more on Ardea deal.

Click to Play Wal-Mart's risk in Mexico bribe probe

Wal-Mart faces significant legal risks after it disclosed that it is investigating its operations in Mexico for possible violations of the U.S. law that prohibits bribery in foreign countries. Photo: Reuters.

Barnes & Noble Inc. BKS �shares were up more than 18% on news that the hedge fund Jana Partners has taken a 12% stake in the book retailer.

Brinker International EAT �rose 10.7% after the Dallas restaurant firm�s adjusted third-quarter earnings of 60 cents a share beat the analyst estimate of 56 cents a share in a survey by FactSet Research.

Central European Distribution Corp. CEDC �rose 14% after it said Russian Standard Corp. agreed to invest $100 million in the Mt. Laurel, N.J., vodka company. Russian Standard�s investment will be handled by Roust Trading Ltd. Also in the spirits business, Beam Inc. BEAM �set plans to buy Pinnacle Vodka and Calico Jack Rum for $605 million in cash.

Shares of Dehaier Medical Systems Ltd. DHRM �climbed 37% Monday after the maker of medical devices said it forged a three-year strategic cooperation agreement with medical firm Timesco of London Ltd. Beijing-based Dehaier will be the exclusive distributor in mainland China for Timesco�s entire Optima series of laryngoscopes. Laryngoscopes are used for tracheal intubations.

Shares of Helix Energy Solutions Group Inc. HLX �were up almost 7% Monday after the company reported better-than-expected first-quarter results. The company�s profit more than doubled on increased revenues in its contracting-services unit and strong prices it received on Gulf Coast crude-oil sales.

Keryx Biopharmaceuticals Inc. KERX �shares were up almost 29% after the company said its partners in Japan are reporting positive results from its study of Zerenex, a drug used to treat end-stage kidney disease patients who are on dialysis.

Decliners

First Solar Inc. FSLR �shares were down 6.8% after Maxim Group cut its rating to sell from hold. Read more on First Solar.

Click to Play Nestlé to buy Pfizer�s baby-food unit

Nestlé SA's $10 billion bid for Pfizer Inc.'s baby food business aims to strengthen the company's footprint in China.

Kellogg Co. K �fell 6% after the cereal and snacks maker warned its full-year earnings will be less than it previously expected because of weakness in its European business and weak volume in some U.S. operations, as well as plans to invest in future growth. Kellogg said it now expects 2012 earnings of $3.18 to $3.30 a share. Analysts polled by FactSet Research currently had a $3.48-a-share estimate for full-year 2012 results.

NeurogesX Inc. NGSX �stock was down almost 16% to close at 46 cents after the Nasdaq Stock Market informed the pharmaceutical concern that it has failed to meet the minimum market capitalization requirement for continued listing on the exchange.

Otelco Inc. OTT �stock tumbled more than 44% after one of its largest clients, Time Warner Cable TWC �, indicated that it would not renew its contract to acquire wholesale network connections from Otelco.

Rambus Inc. RMBS �was down 8.7% after BWS Financial cut its rating on the chip maker to hold from buy.

Sonic Automotive Inc. SAH �was down 5.4% after it reported first-quarter results that fell short of most Wall Street forecasts.

STMicroelectronics�s STM �U.S.-listed shares were down 9.6% after the company�s joint venture with Ericsson ERIC �(ST-Ericsson) said it would lay off 1,700 workers as part of a restructuring.

Tennant Co. TNC �stock slid 12% on worse-than-expected first-quarter sales, which were partially caused by tightened credit in Europe.

Wal-Mart WMT �slumped 4.7% after the blue-chip discount retailer said it was investigating its Mexico operations because a U.S. law that prohibits bribery in foreign countries may have been violated. Read more on Wal-Mart