By Lu Wang

BLOOMBERG NEWS

Shares of the following companies are having unusual moves in U.S. trading this morning.

Homebuilders retreated after a report from the Commerce Department showed sales of new U.S. homes unexpectedly fell in September. Lennar Corp. (LEN US) declined 6.8 percent to $12.72. Pulte Homes Inc. (PHM US) lost 4.3 percent to $9.17. KB Home (KBH US) slipped 5.4 percent to $14.30. D.R. Horton Inc. (DHI US) erased 4.1 percent to $11.33.

Apollo Group Inc. (APOL US) dropped 16 percent to $61.13 and tumbled as much as 17 percent, the most intraday since April 1. The owner of the University of Phoenix reported said the enforcement division of the Securities and Exchange Commission commenced an informal inquiry into the company's revenue recognition practices.

Chiquita Brands International Inc. (CQB US) rose 11 percent to $16.43 after climbing as much as 14 percent, the most intraday since Aug. 7. The seller of bananas and other produce said that, excluding some items, it earned 20 cents a share in the third quarter. Analysts, on average, expected the company to post a loss of 15 cents, according to a Bloomberg survey.

Goodyear Tire & Rubber Co. (GT US) plunged 25 percent to $12.53 for the steepest loss in the Standard & Poor's 500 Index. The largest U.S. tiremaker forecast an operating loss in North America this quarter.

Other auto-parts makers also declined. Cooper Tire & Rubber Co.

Gulfmark Offshore Inc. (GLF US) slipped 8.2 percent to $30.09 after dropping as much as 10 percent, the most intraday since April 16. The company, which transports drilling materials and supplies to offshore oil facilities, said it had earnings of 50 cents per share, less than the 88-cent average per-share estimate of analysts surveyed by Bloomberg.

Harris Corp. (HRS US) advanced 7.1 percent to $40.64 for the biggest gain in the S&P 500 index. The maker of military radios boosted its forecast, projecting profit of at least $3.85 a share for the year. The company had previously predicted $3.50 at most.

Illumina Inc. (ILMN US) sank 16 percent to $35 and tumbled 18 percent earlier, the most intraday since October 2008. The maker of equipment to analyze DNA said that, excluding some items, it expects to earn 25 cents a share at most in the fourth quarter. That trailed the 27-cent average estimate from analysts in a Bloomberg survey.

Level 3 Communications Inc. (LVLT US) declined 9.6 percent to $1.23 and slipped 14 percent earlier, the most intraday since July 31. The network operator reported revenue of $916 million in the third quarter, missing the average analyst estimate by 1.1 percent.

L-1 Identity Solutions Inc. (ID US) dropped 9 percent to $5.75 and fell earlier to $5.67, the lowest intraday price since April 3. The maker of security software reported projected that it will have revenue for 2010 of at most $775 million, lower than the average analyst estimate of $811.7 million.

Massey Energy Co. (MEE US) slipped 8.5 percent to $28.64 after sinking as much as 8.8 percent, the most intraday since July 6. The fifth-largest U.S. coal producer said third-quarter profit plunged 68 percent as the recession cut demand for the power plant fuel. The company again reduced its 2009 production estimate.

National Instruments Corp. (NATI US) gained 5.8 percent to $28.23 and advanced 6.4 percent earlier, the most intraday since June 1. The maker of industrial testing equipment reported earnings of 14 cents per share, compared with the average analysts' estimate of 10 cents in a Bloomberg survey.

Norfolk Southern Corp. (NSC US) gained 3.7 percent to $47.77 and increased 8 percent earlier, the most intraday since Aug. 7. The fourth-largest U.S. railroad reported profit of 81 cents a share in third quarter, beating the average analyst estimate by 2 cents.

NutriSystem Inc. (NTRI US) advanced 11 percent to $20.97 after rising earlier to $21.48, the highest intraday price since September 2008. The company, which sells prepared meals to help clients lose weight, posted earnings excluding some items of 27 cents a share in the third quarter topping the average analyst estimate by 13 percent.

Panera Bread Co. (PNRA US) surged 8.9 percent to $60.02 for the biggest gain in the Russell 1000 Index. The chain of bakery cafes said third-quarter adjusted profit was 65 cents per share, 12 percent more than the 58-cent average estimate of analysts in a Bloomberg survey.

Psychiatric Solutions Inc. (PSYS US) fell the most in Russell 2000 Index, tumbling 25 percent to $18.02. The provider of behavioral-health programs to children reduced its full-year forecast after third-quarter profit missed analysts' estimates.

Quantum Corp. (QTM US) rose 14 percent to $1.86 and surged earlier to $2.03, the highest intraday price since April 2008. The San Jose, California-based maker of backup and archival programs for computers posted earnings excluding some items of 8 cents a share in the fiscal second quarter, beating the average analyst estimate.

SAP AG (SAP US) lost 8.2 percent to $46.98 and slumped 8.5 percent earlier, the most intraday since October 2008. The world's biggest maker of business-management software cut its sales forecast for the year as clients in emerging markets and Japan spent less than it anticipated.

Sealed Air Corp. (SEE US) added 3.6 percent to $20.57 and jumped 7.7 percent earlier, the most intraday since May 4. The maker of Bubble Wrap shipping products increased its full-year earnings forecast after third-quarter profit topped the average analyst estimate by 16 percent.

SPX Corp. (SPW US) fell 12 percent to $53.60 for the biggest intraday decline since April 13. The manufacturer of power-plant cooling systems lowered its full-year earnings forecast after third-quarter profit tumbled 61 percent.

Total System Services Inc. (TSS US) slid 6.8 percent to $15.43 and slipped 11 percent earlier, the most intraday since April 29. The credit-card processor was downgraded to "equal- weight" from "overweight" at Stephens Inc.

Unisys Corp. (UIS US) jumped 10 percent to $26.50. The computer-services manager reported profit of $1.48 a share in the third quarter, exceeding the estimate of 50 cents from Wells Fargo & Co.

ValueClick Inc. (VCLK US) slumped 15 percent to $10.56 after falling as much as 19 percent, the most intraday since July 2008. The Internet advertising company was downgraded to "hold" from "buy" at Needham & Co.

Visa Inc. (V US) climbed 3.5 percent to $76.50 and climbed earlier to $77.82, the highest intraday price since July 2008. The world's biggest payments network posted results that exceeded most analysts' forecasts and said a yearlong skid in consumer spending has ended.