Stent and medical device maker Boston Scientific saw its preliminary fourth-quarter 2005 sales dip 3.1% to $1.54 billion, failing to meet analysts’ general expectations of $1.59 billion, as increased competition from Johnson & Johnson’s rival Cypher stent ate into the group’s market share.

For the quarter, worldwide stent sales dropped 12.3% to $640 million from $730 million for the same period of last year, with worldwide sales of the company’s Taxus Express2 stent of $606 million and $398 million in the USA.

On the plus side, full-year 2005 sales climbed 12% to $6.28 billion, with global stent sales up 15% at $2.69 billion, helped by a strong performance of Taxus both worldwide and in the USA, rising 19% to $2.1 billion and 12% to $1.76 billion, respectively.

But investor confidence waned on the prospect of continued competition from Johnson & Johnson’s Cypher stent, with shares slipping 1.4% to close at $25.88 after a bout of frenzied trading on Monday. Heightened shareholder activity was also sparked by the group’s confirmation of its $25 billion bid to take over medical device maker Guidant, again going head-to-head with J&J, which made an offer of $21.5 billion late last year.