Oct. 20 (Bloomberg) -- The following companies are having unusual price changes in U.S. trading. Stock symbols are in parentheses, and share prices are as of 4 p.m. in New York.

Energy and oil-related shares jumped after Halliburton Co. (HAL US), the world's second-largest oilfield-services provider reported profit that beat some analysts' estimates and Oppenheimer & Co. boosted the ratings for crude producers including Exxon Mobil Corp. (XOM US).

Halliburton climbed 14 percent to $20.80. Exxon increased 10 percent to $74.99. ConocoPhillips (COP US) rose 9.9 percent to $57.73. Chevron Corp. (CVX US) added 12 percent to $69.61. Hess Corp. (HES US) gained 13 percent to $58.38. Suncor Energy Inc. (SU US) climbed 15 percent to $25.24.

Chesapeake Energy Corp. (CHK US) jumped 14 percent to $23.32. Cabot Oil & Gas Corp. (COG US) gained 11 percent to $28.86. El Paso Corp. (EP US) rallied 15 percent to $9.19. Noble Energy (NBL US) advanced 12 percent to $49.74. National-Oilwell Varco Inc. (NOV US) increased 22 percent to $31.26.

Anadarko Petroleum Corp. (APC US) added 12 percent to $37.41. Plains Exploration & Production Co. (PXP US) jumped 19 percent to $25.22. Southwestern Energy Co. (SWN US) increased 16 percent to $33.62. Weatherford International Ltd. (WFT US) rose 15 percent to $16.96.

Amag Pharmaceuticals Inc. (AMAG US) fell 12 percent to $32.24 for the biggest retreat since April 9. The company said it must supply further information to U.S. regulators before they will consider approving the anemia treatment ferumoxytol.

American International Group Inc. (AIG US) climbed 10 percent to $2.31. Prudential Plc is in advanced talks with investment funds in China and the Middle East to help finance a $15 billion offer for AIG's Asian business, the Sunday Times reported, without saying where it got the information.

AT&T Inc. (T US) added 6.7 percent to $26.99. The largest U.S. phone company secured a $600 million contract from the Tennessee government to overhaul the state's network.

BPZ Resources Inc. (BPZ US) gained 19 percent to $9.70, the biggest gain since Sept. 18. The Houston-based oil producer said it received $15 million in World Bank financing to develop its Peruvian oilfield. The funding is part of a $215 million loan program.

Brunswick Corp. (BC US) dropped 22 percent to $4.49, its lowest level since May 1983. The maker of Sea Ray yachts and Life Fitness cardiovascular machines was cut to below investment grade and is still under review at Moody's, which cited concern a contraction in consumer spending will ``put pressure on the company's dealer network.''

Ciena Corp. (CIEN US) gained 13 percent to $8.75. Bank of America Corp. said cash balances at Ciena and Tellabs Inc. (TLAB US) would provide support to the shares. Analyst Tim Long recommended that investors ``aggressively'' buy shares of Ciena, the maker of network equipment for AT&T Inc., given its business prospects. Investors are also undervaluing shares of Tellabs, the analyst said. Tellabs rose 7.7 percent to $3.91.

Copa Holdings SA (CPA US) climbed 19 percent to $29.66, the steepest gain since December 2005. The operator of Panama's Copa Airlines was raised to ``strong buy'' from ``outperform'' by analyst Duane Pfennigwerth at Raymond James & Associates.

Developers Diversified Realty (DDR US) fell 14 percent to $14.17, the lowest level since March 2001. The Beachwood, Ohio- based mall owner plants to reduce leverage by an unspecified amount after bankrupt California retail chain Mervyn's said Oct. 17 that it will close its 38 stores in Developers Diversified facilities.

Emcore Corp. (EMKR US) rose 18 percent to $4.35. The solar- power company may rise to $10 a share in two years if its plan to build a more efficient solar cell catches on, Barron's said, citing Chris Chaney, an analyst at Stanford Financial Group Co.

Ericsson AB American depositary receipts (ERIC US) jumped 16 percent to $8.03 in the biggest rally since July 2003. The world's largest maker of wireless networks said third-quarter profit beat analysts' estimates as sales and job cuts in North America surged.

General Growth Properties Inc. (GGP US) fell 8.7 percent to $5.59. The mall owner may sell up to $2 billion in preferred shares to investors including private equity and hedge funds, the Wall Street Journal reported.

HLTH Corp. (HLTH US) dropped 13 percent to $7.96, the biggest decline since May 2003. The company and its subsidiary WebMD Health Corp. (WBMD US), owner of the WebMD Web site, gave up plans to merge, citing ``uncertainty'' in financial markets and trouble finding a buyer for a second HLTH division. WebMD climbed 26 percent to $19.10.

Hasbro Inc. (HAS US) fell 4.2 percent to $28.87. The world's second-largest toymaker reported third-quarter profit margins of 55.9 percent, lower than the 57 percent estimated by Barclays Plc analyst Felicia Kantor Hendrix.

Hormel Foods Corp. (HRL US) fell 11 percent to $30.16 for the biggest plunge since March 2000. The maker of Spam luncheon meat cut its 2008 earnings forecast to $2.03 to $2.09 a share from an earlier prediction of $2.22 to $2.28 because of higher costs and the decline in global financial markets.

Juniper Networks Inc. (JNPR US) rose 11 percent to $19.98. The second-largest maker of networking equipment was reiterated a ``buy'' at Stifel Nicolaus, which said the company may increase its technical lead in the edge routing market.

Landry's Restaurants Inc. (LNY US) rallied 28 percent to $11.66 for the biggest gain since at least August 1993. The owner of The Crab House and Rainforest Cafe chains said it approved a lowered, $13.50-a-share takeover offer from Chief Executive Officer Tilman Fertitta due to instability in the credit markets.

Las Vegas Sands Corp. (LVS US) lost 6.1 percent to $12.26. The second-biggest casino operator by market value is in discussions with banks as it considers revising the terms of the loans it's seeking for Macau projects.

Wynn Resorts Ltd. (WYNN US), bigger rival of Las Vegas Sands, slipped 8.9 percent to $52.41.

Marsh & McLennan Cos. (MMC US) rose 8.7 percent to $27.86 for the biggest gain since October 2004. The second-biggest insurance broker was added to the ``conviction buy'' list at Goldman Sachs Group Inc. Insurers may raise prices as their results weaken from credit-related investment losses, which would increase fees that Marsh gets for matching buyers and sellers of coverage, Goldman said.

Melco Crown Entertainment Ltd. ADRs (MPEL US) surged for a second day, rising 37 percent to $4.45. The casino venture between Australian billionaire James Packer and Macau magnate Stanley Ho's son Lawrence said its second Macau casino project, City of Dreams, will open on schedule and is financed.

Midway Games Inc. (MWY US) slid 12 percent to $1.10, the lowest level since shares began trading in 1996. The video-game publisher controlled by billionaire Sumner Redstone posted a third-quarter loss of 70 cents a share, compared with a previous estimate of 49 cents.

Mosaic Co. (MOS US) rose 16 percent to $38.93. Shares of the world's largest producer of phosphates gained on speculation Cargill Inc. may take advantage of a plunge in the company's shares this year to increase its majority stake, according to Mark Gulley, an analyst at Soleil Securities.

NRG Energy Inc. (NRG US) rose 29 percent to $25 for the steepest gain since it began trading in December 2003. Exelon Corp. (EXC US), the biggest U.S. operator of nuclear power plants, made an unsolicited offer to buy NRG for $6.2 billion.

Other power producers also advanced. AES Corp. (AES US) jumped 21 percent to $9.89. Reliant Energy Inc. (RRI US) gained 17 percent to $6.06. Public Service Enterprise Group Inc. (PEG US) rose 14 percent to $30.85. Allegheny Energy Inc. (AYE US) Dynegy Inc. (DYN US) added 13 percent to $32.97.

Panasonic Corp. ADRs (PC US) climbed 12 percent to $16.49, the highest level since Oct. 3. The world's largest maker of consumer electronics may beat its first-half operating profit forecast, according to an Oct. 18 report in the Nikkei newspaper. The report ``instills confidence'' in the company, Goldman Sachs Group Inc. said in a note to investors today.

Praxair Inc. (PX US) added 11 percent to $71.02, the highest since Oct. 3. The largest industrial-gas producer in the Americas was raised to ``buy'' at Merrill Lynch & Co.

Research In Motion Ltd. (RIMM US) fell 8.6 percent to $53.91. Pacific Crest Securities called sales of its new Pearl Flip model ``disappointing,'' while Morgan Keegan & Co. cut its sales and earnings estimates on the Blackberry phone maker, citing ``substantial worldwide damage done to the economic outlook since September.''

SanDisk Corp. (SNDK US) fell 7 percent to $14.42, the lowest price since Sept. 15. Toshiba Corp., the world's second-largest flash-memory maker, plans to buy 30 percent of production capacity at its venture with SanDisk to get cheaper access to manufacturing equipment.

Smithfield Foods Inc. (SFD US) added 12 percent to $15.25 for the biggest gain since Oct. 1. JBS SA, the world's largest beef packer, is permitted to take over Smithfield's beef-packing unit. Smithfield is the world's largest pork producer.

Sprint Nextel Corp. (S US) rose 16 percent to $3.55. The third-largest U.S. mobile phone-service provider were ``oversold'' and may now be experiencing a ``near-term bounce,'' said Michael Nelson, an analyst at Stanford Group Co. Sprint has lost 73 percent this year, compared with a 33 percent decline for the Standard & Poor's 500 Index.

Synalloy Corp. (SYNL US) lost 8.5 percent to $9.81, the lowest price since December 2005. The Spartanburg, South Carolina-based pipe-metal maker said third-quarter earnings fell to 20 cents a share from 36 cents in the year-earlier period. The company also said ``significant'' raw-material price increases may hurt earnings.

Syneron Medical Ltd. (ELOS US) slid 12 percent to $9.99, the lowest price since August 2004. The maker of medical products said third-quarter profit was as low as 11 cents a share, or 59 percent less than the average analyst estimate in a Bloomberg survey.

Transocean Inc. (RIG US) advanced 13 percent to $79.56. The world's largest offshore driller was raised to ``overweight'' from ``underweight'' at Morgan Stanley, saying small startup drillers will have trouble financing projects amid the credit crunch while ``established players like Transocean'' will benefit.

TRW Automotive Holdings Corp. (TRW US) dropped 6.6 percent to $7.45, the lowest price since shares began trading in February 2004. Keybanc Capital Markets predicted a weak auto market in Europe through 2009. TRW, the world's largest maker of car-safety equipment, gets 57 percent of its revenue from the region, Keybanc said.

To contact the reporter on this story: Lu Wang in New York at lwang8@bloomberg.net

Last Updated: October 20, 2008 16:43 EDT