NEW YORK (MarketWatch) -- Shares of the following companies made notable moves in the U.S. stock market Tuesday:
Casey's General Stores Inc. /zigman2/quotes/208156554/composite CASY -1.94% shares rose almost 10% after the convenience-store operator said it would begin talks with an unnamed suitor that made a preliminary offer that tops a $38.50-a-share offer from Couche-Tard .
Enterprise GP Holdings LP shares jumped almost 12% after the company and Enterprise Products Partners LP /zigman2/quotes/205356165/composite EPD -1.00% announced a unit-based merger.
Kopin Corp. /zigman2/quotes/203584478/composite KOPN -1.55% shares rallied 5.7% after Barron's said the company could benefit from increased demand for its wafers and components, used in power-amplifier circuits within smart phones.
Oracle Corp. /zigman2/quotes/202180826/composite ORCL -0.60% shares gained almost 6% after the software giant named former Hewlett-Packard Co. /zigman2/quotes/203461582/composite HPQ -3.46% Chief Executive Mark Hurd as one of its presidents. Read more about Oracle's shakeup.
ResCare Inc. shares advanced 6% after the home-care provider said it will be acquired by Canadian private-equity firm Onex Corp.
Biovail Corp. and Valeant Pharmaceuticals International gained, the former up 9.6% and the latter 6.4%, after the drug developers said in a regulatory filing they would cut their workforce by about 25% as part of their merger agreement announced in June.
Barclays PLC /zigman2/quotes/206581728/composite BCS -2.95% shares declined 5.7% after the British bank promoted Robert Diamond Jr. to the post of chief executive. Read about the executive moves at Barclays.
Europe jitters all over again
Markets are jittery again as fresh concerns emerge about European banks, leaving the euro and financial shares on both sides of the Atlantic under pressure.
Brooks Automation Inc. shares fell more than 13% and KLA-Tencor Corp. /zigman2/quotes/209248041/composite KLAC -2.67% shares declined 5.6% after Barclays Capital cut from overweight to equalweight the suppliers of equipment used in making microchips.
China Sky One Medical Inc. shares slid 31% after the Chinese drug maker cut its revenue outlook for the year and said its chief financial officer resigned.
GT Solar International Inc. /zigman2/quotes/222494847/composite SOLR -2.29% shares dropped 11.6% after the manufacturer disclosed that a shareholder planned to sell 10 million shares.
Idenix Pharmaceuticals Inc. shares tumbled 47% after the company said it had received verbal notice from U.S. regulators that two experimental hepatitis C treatments were on hold.
Lincoln National Corp. /zigman2/quotes/205272400/composite LNC -3.81% shares slid 4.5% after the government announced it would sell warrants in the insurer and Hartford Financial Services Group Inc. /zigman2/quotes/207281914/composite HIG -2.50% . Read more about Lincoln and Hartford.