Smiths Group, the maker of medical devices, airport scanners and other equipment, has rejected a £2.45bn approach for its biggest division Smiths Medical, it announced after the close of trading on Friday. It said it had carefully considered the approach, concluding that continuing discussions on the basis of a sale at that level would not be in shareholders' best interests."In reaching this conclusion, the board has taken into account the quality and highly cash generative nature of Smiths Medical, both standalone and in the context of the group as a whole," the company said.It did not say who had made the bid, but a report in the Financial Times said that the private equity group Apax had approached Smiths late last year.Smiths Medical accounted for about 35% of the company's sales last year.Smiths is not the only company in the medical sector to be involved in M&A excitement today. Shares in Smith & Nephew quickly gave up earlier gains to finish flat after the medical devices group denied reports that it is in any talks that could lead to a merger or takeover.