Shares of Universal Technical Institute ( UTI - Get Report) were among the NYSE's losers Thursday, slumping 26% after the company warned that second-quarter and full-year sales would be below forecasts.

The operator of vocational schools estimates sales of $88 million to $89 million for the quarter ended March 31. Analysts polled by Thomson First Call project sales of $90.3 million. "A confluence of external factors and internal issues have negatively impacted our ability to recruit, show and retain students as planned," the company said. "While we have worked diligently to overcome the obstacles, and have realized some recruit success as a result of our efforts, we now believe it would be very difficult to overcome the issues inside of this fiscal year."

Universal Technical Institute lowered its fiscal 2006 sales growth forecast to 11% to 13% from an earlier view of 19% to 21%. The company now expects net income margins, excluding stock-based compensation costs, of 9% to 10%, down from an earlier forecast of 11.5% to 12%. Analysts project 2006 earnings of $1.37 a share and sales of $365.6 million. Shares were trading down $7.55 to $21.80.

Tesoro ( TSO) shares fell 2% after the oil refiner said first-quarter earnings would be below expectations. The company sees earnings of 60 cents a share, below the 74 cents a share that analysts project. Tesoro said that the recent spike in crude oil prices hurt its results. "The over $6 per barrel increase impacted the company's hedge position on approximately 2.5 million barrels of long-haul crude oil and long-term blendstock supplies," Tesoro said. Shares were trading down $1.45 to $70.98.

Shares of Polaris Industries ( PII - Get Report) fell 3% after the maker of snowmobiles posted in-line first-quarter earnings but warned that second-quarter and full-year results would be lower than expected. For the quarter ended March 31, Polaris posted earnings from continuing operations of $11.2 million, or 26 cents a share, on revenue of $333.5 million. Analysts expected earnings of 26 cents a share on revenue of $332.4 million. During the year-earlier quarter, the company earned $17.9 million, or 40 cents a share, on revenue of $358.3 million.

Looking ahead, Polaris sees second-quarter earnings from continuing operations of 50 cents to 54 cents a share, below analysts' average estimate of 68 cents a share. For the full fiscal year, the company anticipates earnings of $3.08 to $3.20 a share. Analysts project earnings of $3.30 a share. Polaris said second-quarter shipments would decline because of lower snowmobile orders and North American dealers reducing their ATV inventories. The company's shares recently had shed $1.63 to $48.95.

Vulcan Materials ( VMC - Get Report) rose 4% after the maker of construction materials lifted its first-quarter earnings estimate. The company now sees earnings of 69 cents to 70 cents a share, including a one-time gain of 7 cents a share. Excluding the gain, the company anticipates earnings of 62 cents to 63 cents a share, up from an earlier view of 50 cents to 60 cents a share. Analysts project earnings of 57 cents a share. During the year-earlier quarter, the company earned 21 cents a share. "Continuing strong demand and favorable weather conditions resulted in record first quarter sales for all key products," Vulcan said. Shares were trading up $3.52 to $91.48.

Shares of New York & Co. ( NWY) fell 3% after the retailer of women's clothing cut its first-quarter earnings and sales forecasts. The company now sees earnings of 9 cents to 13 cents a share on sales of $264 million to $269.5 million. Previously, the company predicted earnings of 20 cents to 23 cents a share on sales of $277 million to $282 million. Analysts project earnings of 21 cents a share on sales of $275.4 million.

The company blamed the revised guidance on lower-than-expected comparable-store sales for April. Based on the month-to-date trends, the company projects April sales of $88.5 million to $94 million, with a 1% to 6% same-store sales increase. "This positive trend represents a significant improvement versus last month; however, is less than required to achieve the current earnings guidance range," the company said. Shares were trading down 56 cents to $14.51.

NYSE volume leaders included Medtronic ( MDT), down 40 cents to $50.64; Advanced Micro Devices ( AMD - Get Report), down $2.87 to $32.55; Boston Scientific ( BSX), down 60 cents to $21.56; General Electric ( GE - Get Report), down 19 cents to $34.27; Motorola ( MOT), up 10 cents to $24.08; Nortel Networks ( NT), up 4 cents to $2.85; Ford ( F), up 2 cents to $7.30; and Micron Technology ( MU), down 6 cents to $15.26.

Nasdaq volume leaders included Intel ( INTC), up 20 cents to $19.32; Sirius Satellite Radio ( SIRI), up 2 cents to $5.22; Sun Microsystems ( SUNW), up 3 cents to $5.22; Applied Materials ( AMAT), up 51 cents to $17.93; SanDisk ( SNDK), up $2.61 to $62.08; Cisco ( CSCO), up 34 cents to $21.36; Apple Computer ( AAPL), down 17 cents to $66.54; Microsoft ( MSFT), down 4 cents to $27.16; and JDSU ( JDSU), up 3 cents to 3.65.