Johnson & Johnson (JNJ) is in talks to acquire the U.S. operations of Synthes Inc, according to reports, a deal which, if consummated, would be one of the largest healthcare transactions in recent times.

The Wall Street Journal reported late Friday afternoon that J&J is in talks to buy the Swiss-based medical-device maker for close to $20 billion, citing “people familiar with the matter.” JNJ would not confirm the story. 

"As a matter of policy we don't comment on speculation," a spokesman for the company told FOX Business.

The deal was still not done, as the Journal reported that one person warned that the talks were “fragile”. JNJ has been looking for a medical equipment company to acquire, as its medical device division, which accounted for 40% of its 2010 revenue, is its largest business segment.

Shares of Johnson & Johnson rose 1% in Friday’s session, closing the day at $60.56 a share. The stock was down slightly in after-hours trading. Shares of Synthes, which are traded on the Swiss exchange, were up 17% since mid-March.