Despite some problems, demand for Guidant products is seen rising

Boston Scientific tabled a $25bn (�14bn) bid, saying it saw a chance to grow Guidant's heart rhythm products.

Guidant has already agreed to be bought by Johnson & Johnson (J&J) for $21.5bn, although the price was cut after problems with a number of products.

Shares in Guidant rose nearly 10% to $67.67 in early New York trade.

'More diversified'

"This is a phenomenal move," said Mark Landy, an analyst at Susquehanna Financial Group. He called the offer a "holiday gift for Guidant" shareholders.

Boston Scientific is "literally telling J&J to put up or shut up", Mr Landy said.

"A $72 bid is hard to ignore" Thomas Gunderson, Piper Jaffray Check Boston Scientific's share price Check Guidant's share price Check J&J's share price

Under the terms of its offer, which is made up from a mix of cash and company equity, Boston Scientific would pay a total of $72 for every Guidant share.

J&J is offering slightly more than $63 per share.

It had originally said it would pay $76, but renegotiated the figure after Guidant had to recall more than 100,000 faulty heart defibrillators.

Guidant was also investigated over its failure to inform doctors about potential defects in some of its products.

J&J almost called the deal off, and only returned to the negotiating table after it was sued by Guidant.

'Hard to ignore'

Despite the firm's problems, both J&J and Boston Scientific are attracted by the growth potential for heart devices.

They reckon that the products would compliment their existing portfolios of devices such as cardiac stents, which are used to keep coronary arteries open and unclogged.

Jim Tobin, president and chief executive of Boston Scientific, said that buying Guidant would allow the firm to become "more diversified, participating in two of the largest medical device markets - interventional cardiology and cardiac rhythm management".