In an unusual positive stock-market move on merger news, shares of Teleflex Inc rose more than $6 in morning trading after the Valley Forge medical-devices maker said it has agreed to pay $1 billion in cash, or $56 a share, for fast-growing Vascular Solutions Inc., which makes heart catheters and other cardiology devices.

Analyst Lewis questioned if Vascular will keep growing so fast. Vascular has a "robust R&D pipeline" of "high growth products" that will complement Teleflex's own products, CEO Benson F. Smith said in the conference call. JPMorgan will help Teleflex finance the deal.

Teleflex shares traded after 1 p.m. at $152.70, up $6.67 for the day. But the stock still trailed its September alltime high of $188.35. Shares fell in October after the company announced a product recall and the planned closing of a North Carolina factory.

CEO Smith said the deal was the latest in a string of Teleflex acquisitions helping the onetime electrical-device supplier boost its profile as a diversified medical-device maker.