The bid rumour, the latest in a long series, emerged in a report in a Swiss newspaper which suggested that an offer worth pounds 21 to pounds 22 a share would be launched by Roche early next week. Cash, a weekly financial publication, claimed the two companies were in talks and the Basle-based Roche planned to sell off Zeneca's agrochemicals and specialty chemicals operations, keeping only the drugs business.
Neither company would comment yesterday. A representative for Roche said: "We've heard the rumours before and we didn't comment then and we are not commenting now."
The Swiss company has substantial cash resources and is thought to be interested in making acquisitions, but analysts played down the latest twist to what has become a long-running saga. James Dodwell, a pharmaceuticals watcher at Barclays de Zoete Wedd, said the two companies would fit together reasonably well. Roche had a lot of hospital products, while Zeneca's portfolio was strong in drugs targeted at GPs. Zeneca also had a strong franchise in cancer treatments, which Roche lacked, he suggested.
But he said: "Zeneca won't go freely. They want to remain independent and have said they are going to achieve 15 per cent per annum earnings growth for the next five years." Even for Roche, the possible $35bn price tag for the British group would be hard to digest, while the rating might be hard to justify.
The one piece of tangible good news yesterday for Zeneca, headed by chief executive Sir David Barnes, was that a US appeal court had upheld its patent rights over Nolvadex, still the most widely used treatment for breast cancer nearly quarter of a century after its launch. The appeal to the Federal court followed a challenge by Novopharm, a Canadian maker of generic drugs, which had been thrown out by a lower court in Maryland last April. Zeneca said the decision disposed of the proceedings instituted by Novopharm, which had wanted to produce a generic form of the drug.
The decision helps protect Zeneca's US patent until its expiry in 2002, although the company said it would continue patent infringement proceedings against two other companies, Mylan Pharmaceuticals and Pharmachemie, which have submitted applications for generic forms of the drug with America's Food and Drug Administration.