Pharmaceutical company Shire (SHP.L) is considering a 12 billion pound ($18.32 billion) takeover of Actelion Ltd (ATLN.VX) Europe’s biggest biotech firm, Britain’s Sunday Times newspaper reported, citing unnamed sources. An informal approach by Shire was rebuffed several weeks ago, the newspaper said, citing financial industry sources. Shire was willing to pay 160 Swiss francs a share for Actelion, the sources said, a hefty premium to the stock’s Friday closing price of 132 francs.