Sierra Wireless ( SWIR - Get Report) surged more than 10% in after-hours trading Wednesday as the maker of wireless-communications products more than doubled its fourth-quarter profit to $2.4 million, or 9 cents a share, on revenue of $68.3 million. A year ago, the Canada-based company earned $911,000, or 4 cents a share, on sales of $37.6 million. Wall Street was looking for earnings of 7 cents a share on $66.2 million in revenue, according to Thomson Financial. Shares were adding $1.48 to $15.92.

Net1 UEPS Technologies ( UEPS - Get Report) jumped on word that its universal electronic payment system will be used in Grindrod Bank's new retail banking division and that Net1 will additionally assist the South African bank in implementing the business plan and operations. Net1 will be paid fees contingent on the amount of business that uses its technology. Specific monetary terms weren't disclosed. South Africa-based Net1 was gaining $1.70, or 6.3%, to $28.80.

FormFactor ( FORM - Get Report) rose after its fourth-quarter results flew by estimates. The semiconductor-component maker reported a profit of $18.9 million, or 39 cents a share, compared with $10.5 million, or 25 cents a share, a year ago. Revenue shot up 37% to $98.7 million. Analysts were looking for income of 31 cents a share on sales of $95.1 million. Shares of the Livermore, Calif., company were up $1.35, or 3.32%, to $42.

WebEx Communications ( WEBX) was higher after the Internet-service provider said fourth-quarter earnings were up 40% from a year ago on a per-share basis, to $21.8 million, or 42 cents a share, excluding items. Revenue climbed 22% to $101.9 million.

Analysts were seeking a profit of 38 cents a share on sales of $101.4 million. Looking ahead, the Santa Clara, Calif., company expects 2007 earnings to range between $1.60 and $1.70 a share on a non-GAAP basis, and sales should be between $450 million and $465 million. The Street is calling for $1.62 a share on $454.1 million in revenue. Shares were gaining $2.42, or 6.5%, to $39.50.

Shares of Tractor Supply ( TSCO - Get Report) dropped after the Tennessee-based conglomerate issued 2007 earnings guidance of $2.45 to $2.52 a share, which is at least 9 cents below Wall Street expectations. Revenue should be between $2.7 billion and $2.74 billion, roughly in line with estimates, and the farm-products retailer projects a 3% to 4% same-store sales increase.

For the fourth quarter, Tractor Supply reported a profit of $29.5 million, or 72 cents a share, on revenue of $629.9 million. Income beat Street estimates by a penny, but sales just missed the $633.6 million estimate. Shares were losing $2.33, or 4.6%, to $48.

Boston Properties ( BXP - Get Report) shares were lower after the real estate investment trust said it's offering $750 million in exchangeable senior notes, with an additional $112.5 million option for the initial purchasers to cover any overallotments. Shares were down $5.09, or 4%, to $121.