PXRE Group ( PXT) shot up more than 12% in extended trading Wednesday as the Bermuda-based reinsurance company announced it will merge with insurance underwriter Argonaut ( AGII). The planned stock swap will create a new company called Argo Group International, of which roughly 27% will be owned by former PXRE shareholders. Former Argonaut holders will own the rest. PXRE separately reported narrowing losses on plummeting revenue in the fourth quarter. Its shares were surging 55 cents to $5.01 in recent after-hours action. Argonaut stock was up 35 cents, or 1%, to $34.50. PDI ( PDII) shares jumped after the business-services firm swung to a fourth-quarter profit of $4.8 million, or 35 cents a share, compared with a year-ago loss of 83 cents a share. The Saddle River, N.J., company's revenue sank 29% year over year to $55.8 million, but this beats two analysts' estimates by $7.2 million, according to Thomson Financial. Shares were trading up $1.63, or 16.5%, to $11.50. Spectranetics ( SPNC) gained on strong preliminary results from a study of its Turbo-Booster device, which is proposed to help treat blockages in the main artery above the knee. The Food and Drug Administration decided, jointly with Spectranetics, that the study should end early in order that it be submitted for regulatory review. The trial had begun in July. Shares of the Colorado-based company were climbing 62 cents, or 6.3%, to $10.50, in recent after-hours trading.