European shares swung between gains and losses on Tuesday after the benchmark stock index dropped to the weakest level in a month as investors awaited a result from the debt ceiling talks in Washington. The benchmark Stoxx Europe 600 Index slipped 0.2% yesterday hitting the lowest level since September 9, while the Euro Stoxx 50 Index for December settlement fell 0.1% to 2,906 as of 7:11 a.m. London time.