Alcoa ( AA) spiked nearly 5% in after-hours trading Tuesday as the aluminum-products company powered past fourth-quarter Wall Street projections. Excluding restructuring and impairment charges, the Pittsburgh-based company said it earned $644 million, or 74 cents a share -- 179% more than it did a year ago -- on revenue that rose 20% to $7.8 billion.

Analysts polled by Thomson Financial were looking for 65 cents a share on revenue of $7.63 billion. The company also posted 2006 income of $2.5 billion, or $2.90 a share, which represents a 75% jump from last year. Shares were gaining $1.36 to $29.88.

Synchronoss Technologies ( SNCR) shares got a boost after the Bridgewater, N.J.-based software company announced that wireless giant Cingular will use its ActivationNow platform for order management related to Apple's ( AAPL) new iPhone product. Shares were trading up 75 cents, or 5.1%, to $15.52.

Energy company MDU Resources Group ( MDU) rose on news that it's considering selling domestic-power production assets held in its Centennial Energy Resources subsidiary. The Bismarck, N.D.-based company has retained Goldman Sachs as an adviser. Shares were climbing 85 cents, or 3.4%, to $25.75.

Electronics maker Audiovox ( VOXX) gained after it swung to a third-quarter profit. The Happauge, N.Y.-based company said it earned $3.9 million, or 17 cents a share, reversing a loss of $10.3 million, or 46 cents a share, a year ago. Analysts were expecting 15 cents a share. Revenue dipped 2.9% to $151.8 million, but that nonetheless beat the $148.8 million consensus. Shares were up 40 cents, or 2.8%, to $14.80.

Ramtron International ( RMTR) plunged after the semiconductor maker cut its fourth-quarter product-revenue forecast to a range between $9.1 million and $9.2 million, compared with its previous outlook between $10.2 million and $11.2 million. Two analysts are looking for sales of $11.4 million. Shares were sliding 43 cents, or 12.5%, to $3.

Oxford Industries ( OXM) sank on disappointing guidance. The company's fiscal second-quarter results included a profit of $12.2 million, or 68 cents a share, beating estimates by a penny and surpassing last year's $11 million, or 62 cents a share. But the Georgia-based upscale-apparel maker also predicted 2007 earnings of $3 to $3.15 a share on $1.14 billion to $1.16 billion in sales. Wall Street is looking for $3.33 a share on revenue of $1.17 billion. Shares were off $3.39, or 6.8%, to $46.15.

WD-40 ( WDFC) shares foundered after fiscal first-quarter results fell far short of estimates. The San Diego-based lubricant maker saw profits of $5.7 million, or 33 cents a share, down 24.2% from a year ago, and 9 cents below expectations. Revenue increased 7.1% to $72 million, just shy of the $72.5 million consensus. Shares were losing $1.75, or 5.2%, to $31.80.

Nuco2 ( NUCO) slumped after it unveiled a costly restructuring plan that sharply deflated its fiscal 2007 forecast. The company, which makes systems that carbonate fountain beverages, now expects to earn only 50 cents to 55 cents a share in the year ended June 30, vs. its prior range of 80 cents to 85 cents a share. Analysts are projecting 83 cents a share. Revenue is projected at $130 million to $132 million, just missing the $134 million mean estimate. Shares were down $1.23, or 5.2%, to $22.64.