Cinemark, Universal Display, Warner Music: U.S. Equity Movers

Shares of the following companies are having unusual moves in U.S. trading. U.S. exchanges were closed yesterday for Memorial Day. Stock symbols are in parentheses, and prices are as of 10:50 a.m. in New York.

AOL Inc. (AOL US) rose 3.3 percent to $21.31, after climbing as much as 6.4 percent, the most intraday since May 10. The Internet publishing and advertising company was raised to “buy” from “hold” at Benchmark Co. LLC.

BP Plc (BP US) sank 11 percent to $38.30 after plunging as much as 14 percent, the most intraday since at least July 1980. The energy producer abandoned an attempt to plug the well spewing millions of gallons of oil into the Gulf of Mexico and said it will now try to contain the spill by fitting a pipe over the leak later this week to bring the oil to a drillship on the surface.

Companies that provide services for BP on the well also fell. Cameron International Corp. (CAM US) slipped 5.1 percent to $34.35. Transocean Ltd. (RIG US) dropped 7.1 percent to $52.75. Halliburton Co. (HAL US) lost 7.3 percent to $23.02. Anadarko Petroleum Corp. (APC US) slumped 16 percent to $43.94 for the biggest decline in the Standard & Poor’s 500 Index.

Other oil-services or equipment providers also retreated. Diamond Offshore Drilling Inc. (DO US) lost 4.9 percent to $60. National-Oilwell Varco Inc. (NOV US) slid 5.1 percent to $36.20. Smith International Inc. (SII US) fell 4.7 percent to $35.78. FMC Technologies Inc. (FTI US) erased 4.1 percent to $55.74.

Dexcom Inc. (DXCM US) fell 7.8 percent to $9.71, after sinking as much as 11 percent, the most intraday since April 2009. The medical device developer failed to tell U.S. regulators about customer complaints involving broken sensor wires with its glucose monitoring system, according to a warning letter posted on the Food and Drug Administration’s website. The agency urged the company to strengthen precautions in labeling for the product.

ELong Inc. (LONG US) rose 16 percent to $13.59, after climbing to $13.70 earlier, the highest intraday price since Nov. 12. Expedia Inc. (EXPE US) boosted its stake in the Chinese online travel company to 16.9 percent, according to a regulatory filing.

ev3 Inc. (EVVV US) rallied 18 percent to $22.24 for the biggest advance in Russell 2000 Index. Covidien Plc (COV US), the medical-device company spun off from Tyco International Ltd., agreed to buy ev3 for $2.6 billion to add treatments for heart disease.

Genzyme Corp. (GENZ US) rose 1.8 percent to $49.50. The largest maker of genetic disease medicines was raised to “neutral” from “underweight” at JPMorgan Securities Inc. by equity analyst Geoffrey Meacham. The 9-month price estimate is $50 per share.

Icahn Enterprises LP (IEP US) gained 12 percent to $38.54, after jumping to $38.70 earlier, the highest intraday price since May 10. The investment company controlled by billionaire Carl Icahn may rise to as much as $44 a share, its estimated asset value, Barron’s reported, without citing anyone.

Mediacom Communications Corp. (MCCC US) increased 15 percent to $6.12, after rallying as much as 17 percent for the biggest intraday gain since March 2009. The cable television company said it received an offer from its founder, Chairman and Chief Executive Officer Rocco B. Commisso to take the company private for $6 a share.

Oceaneering International Inc. (OII US) dropped 6.7 percent to $43.17, after sliding to $43.14 earlier, the lowest intraday price since July 14. The provider of engineered services and products to the offshore oil and gas industry was cut to “underweight” from “equal weight” by Morgan Stanley.

RadioShack Corp. (RSH US) rose the most in the S&P 500, climbing 6.9 percent to $21.84. Blackstone Group LP is a leading bidder for the U.S. consumer-electronics chain, the New York Post reported, citing unnamed people familiar with the matter. Private equity firms Kohlberg Kravis Roberts & Co., Bain Capital Partners LLC and TPG Inc. are also likely to be involved in the bidding, according to the report. RadioShack, which may sell itself for as much as $3 billion, is looking to complete the deal this summer, the newspaper said.

Regal Entertainment Group (RGC US) fell 4.7 percent to $14.35, after sinking as much as 7.6 percent, the most intraday since May 6. The theater chain operator and rival Cinemark Holdings Inc. (CNK US) were cut to “neutral” from “buy” at Janney Montgomery Scott LLC on weak 2010 box office results. Cinemark slipped 3.8 percent to $15.38.

Rogers Corp. (ROG US) climbed 4.1 percent to $29.74, after rising as much as 9.6 percent, the most intraday since April 6. The maker of components used by telephone, technology and defense companies raised its forecast for second-quarter profit to as much as 45 cents a share. Analysts had expected 31 cents a share.

Ryanair Holdings Plc (RYAAY US) rose 7.1 percent to $25.22, after gaining as much as 8.3 percent, the most intraday since April 1. Europe’s largest discount airline is not “actively” trying to pursue negotiations with Boeing Co., Deputy Chief Executive Officer Michael Cawley told reporters at a press conference in Dublin today. Negotiations with Boeing about a possible order for 200 planes broke down in mid-December.

Universal Display Corp. (PANL US) climbed 14 percent to $17.64, after advancing to $18.04 earlier, the highest intraday price since February 2008. The developer of technologies used in flat panels was raised to “buy” from “hold” at Canaccord Genuity Corp.

Warner Music Group Corp. (WMG US) fell 13 percent to $5.30, after plunging as much as 15 percent, the most intraday since Nov. 24. Edgar Bronfman Jr., chief executive of the world’s third-largest record label, faces insider trading charges in a trial between Vivendi SA (VIV FP) and its former Chief Executive Officer Jean-Marie Messier that starts tomorrow in Paris. Bronfman became a Vivendi vice chairman following the $34 billion sale of Seagram Co. to Vivendi in 2000. Thierry Marembert, a lawyer for Bronfman, said Bronfman’s transactions were entirely proper.