Shares in Smith & Nephew quickly gave up earlier gains after the medical devices group denied reports that it is in any talks that could lead to a merger or takeover.A report in the Daily Telegraph said that it was set to enter talks with the private equity backed US orthopaedics group Biomet about a possible £15bn merger.However, S&N responded later in the morning that it was making an exception to its policy of not commenting on press speculation to clarify that "it is not engaged in any discussions which could lead to a merger or a takeover involving the company."Despite giving up their earlier gains, shares in S&N are still up 5% on the week, having jumped on Monday after a report that it rejected a bid from the US consumer healthcare and pharmaceuticals group Johnson & Johnson.