Citrix Systems ( CTXS) shares were leaping 10.9% in after-hours trading Tuesday as the company said fourth-quarter earnings rose to $73 million excluding items, or 39 cents a share, edging past estimates by a penny.

Last year, the Fort Lauderdale, Fla., infrastructure-software company made $67 million, or 36 cents a share. Revenue climbed 19% from last year to $321 million, topping the $311.4 million consensus, according to Thomson Financial. The results were called preliminary due to an ongoing internal stock-option grant review. Shares were up $3.25 to $33.12.

Quanta Services ( PWR) soared after the Houston-based contractor drove up its fourth-quarter estimates. The company -- which deals in installation and maintenance relating to electricity and gas, among other things -- now expects to earn between 19 cents and 20 cents a share, excluding items. Previous guidance called for 11 cents to 14 cents a share. Sales are estimated at $590 million to $600 million, up from the prior range of $500 million to $525 million. Analysts are looking for 14 cents a share on $518.7 million revenue. Shares were adding $1.50, or 7.5%, to $21.40.

RF Micro Devices ( RFMD) rose after the company more than tripled its earnings in the quarter ended Dec. 31, with income totaling $59.3 million, or 26 cents a share, on $281.1 million revenue. This compares with last year's $14.7 million, or 7 cents a share, on sales of $208 million. The Greensboro, N.C., maker of mobile-communications systems was rising 55 cents, or 8%, to $7.43.

Ablest ( AIH) climbed after it announced it may go private. Board member Charles Heist, Chief Executive Kurt Moore and The Burton Partnership have collaboratively offered to buy the Tampa, Fla., staffing-services company for $7.50 a share. Shares were adding 45 cents, or 6.4%, to $7.45.

Synergx Systems ( SYNX) announced that its Casey Systems unit had won a $350,000 bid for its communications equipment to be used in three New York City subway stations. The Syosset, N.Y., small-cap was up a dime, or 6%, to $1.76.

Candela ( CLZR) plunged after the Wayland, Mass., maker of laser-based cosmetic-surgery systems said it earned less than a quarter of what it did last year. Fiscal second-quarter earnings came to $1 million, or 4 cents a share, compared with $4.5 million, or 19 cents a share, a year ago. Revenue, at $37.4 million, was a hair below last year's sales. CEO Gerald Puorro conceded that the company's previous revenue growth target for fiscal 2007 was too optimistic and lowered it to between 7% and 9%, down from 15% to 18%. Shares were declining $2.15, or 18.1%, to $9.75.

Supertex ( SUPX) also slid on narrowed profits, as the Sunnyvale, Calif., semiconductor-components maker posted profits of $5.5 million, or 39 cents a share, for the quarter ended Dec. 30. This compares with $3.7 million, or 26 cents a share, a year ago. Sales jumped 21% year over year to $24.1 million, but analysts were seeking $27 million. Shares were falling $3.93, or 10.6%, to $33.00.

QLogic ( QLGC), another California-based semiconductor company, likewise slipped on a steep decline in non-GAAP profits. Income came to $44.9 million, or 28 cents a share, compared with year-ago earnings of $31.4 million, or 19 cents a share. This beat the Street forecast of 26 cents, and the 22% revenue climb from last year, to $157.6 million, more or less reached the consensus. But shares were down $1.13, or 5.6%, to $18.99.

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