The acquisition was quietly revealed in a set of accounts just filed for Mednova, although the buyout was actually completed in the later part of 2005.

Abbott Laboratories, which already held a stake in the Mednova, was just one of a number of shareholders in the company. Others included Enterprise Ireland, which invested Euro1m in the stent developer between 1997 and 1999, venture capital outfits including Schroder Ventures, Wellcome, Hg Capital, and management.

Mednova was founded and headed by John O'Shaughnessy. Losses at the company had soared as money was ploughed into research and development of stents, which are primarily used to reopen blocked or partly-blocked arteries, and filters used during surgery. In 2003 it posted a loss of Euro12m, bringing its retained loss at the time to Euro61m.

Its turnover in 2003 was just slightly over Euro2m. The previous year Mednova wrote off a Euro6.5m investment in subsidiary Carotid Interventional Systems. By the end of 2004, Mednova's accumulated losses had dropped slightly to just over Euro59.5m.

Mednova has now ceased trading as a separate entity.

Abbott and Mednova have been engaged in a number of stent trials in the past, while Abbott has been distributing Mednova products.

Abbott Laboratories employs around 3,400 people here and last week agreed to sell its diagnostics unit, which includes sites in Longford and Sligo, to General Electric for $8.13bn.

The two Irish plants employ 1,300 people.

Last year Indian firm Wockhardt paid over Euro118m to buy Tipperary-based generic drug manufacturer Pinewood Laboratories.