Boston Scientific Corp. (BSX) on Wednesday cut its earnings and sales outlook for 2005 due to an expected decline in the global market share of its Taxus stent systems (search) and on costs related to four recent acquisitions, sending its shares 2.5 down percent.

The Natick, Mass.-based company cut its outlook for 2005 earnings to a range of $1.85 to $2 per share excluding items, down from its prior view of $2 to $2.20 per share.

Analysts on average had expected 2005 earnings of $2.06 per share, according to Reuters Estimates.

Boston Scientific said it expects 2005 worldwide sales in the range of $6.35 billion to $6.57 billion. Worldwide sales of the Taxus drug-coated stents are expected to range between $2.62 billion and $2.76 billion.

In February, the company had forecast sales of $6.4 billion to $6.7 billion, including worldwide Taxus sales of $2.7 billion to $3 billion.

The company lowered its growth outlook from the cardiology business to a range of 11 percent to 16 percent, from its previous expectation for growth of 14 percent to 20 percent.

"Our stent business in the U.S. is extremely strong and extremely stable," said Paul LaViolette, chief operating officer of the company, in a conference call with analysts.

He said there has been "no erosion" in its share of the U.S. market, where it is locked in a fierce battle with Johnson & Johnson (JNJ), which markets the only other drug-coated stent approved for sale in the United States.

However, Boston Scientific does expect U.S. prices to erode by 2 percent or less per quarter as the companies continue to spar for market share.

Drug-coated stents present an advance over conventional, uncoated stents. The devices prop open diseased heart arteries that have been cleared of fatty deposits.

Boston Scientific on the call said it expects U.S. Taxus market share of 57 percent to 61 percent, and worldwide market share of 52 percent to 55 percent.

The company's shares fell 75 cents to $29.86 on the New York Stock Exchange.