Beach Energy BPT.AX fell nearly 4% after the contractor of the Waitsia gas project, Clough Ltd, was placed under voluntary administration. Dec 6 (Reuters) - Australian shares slipped on Tuesday ahead of a central bank policy decision, as strong U.S. data sparked fears that the Federal Reserve could hike interest rates for longer. Data showed U.S. services industry activity unexpectedly picked up in November in the latest sign of underlying economic momentum that could keep the Fed on alert to tighten policy further as it fights high inflation.